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Aflatoxins. A Review of Human Carcinogens: Chemical Agents and Related Occupations

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... The study of genotoxicity is indispensable for comprehending and evaluating the potential risks linked with exposure to diverse harmful substances. Genotoxicity boasts a broad scope, encompassing several areas 16 . ...
... These alterations disturb the normal regulatory mechanisms governing cell growth and division. Numerous carcinogens exhibit genotoxic properties, instigating DNA damage and mutations 16 . ...
... Genotoxicity in the field of emerging technologies: Nextgeneration sequencing, genomics, and other high-throughput technologies empower researchers to evaluate genotoxic effects across the entire genome. This facilitates a more exhaustive analysis of the repercussions of exposures 16 . ...
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Genotoxicity encompasses the properties of chemical agents that cause damage to genetic material, potentially leading to mutations and cancer. This damage includes DNA strand breaks, chromosomal fragmentation, and mutations, impacting both somatic and germ cells. Genotoxic agents, such as environmental pollutants, industrial chemicals, pharmaceuticals, and natural compounds, pose significant health risks. The field of Genetic Toxicology has advanced significantly with the development of techniques like the Ames Assay and Comet Assay for detecting genetic damage. While all mutagens are genotoxic, not all genotoxic substances are mutagenic. Genotoxic effects can induce mutations, disrupt cellular events, and cause direct DNA damage. Cells employ mechanisms like DNA repair and apoptosis to counteract these effects. The consequences of genotoxicity are severe, potentially leading to cancer, hereditary genetic defects, and environmental health hazards. This underscores the need for comprehensive risk assessment and mitigation strategies. The advancement in our understanding and detection of genotoxicity is crucial for safeguarding public health and the environment.
... Within these species, P. nordicum has been described as the main OTA producer in dry-cured meat products and cheeses [151]. This mycotoxin is nephrotoxic, hepatotoxic, teratogenic, immunotoxic and has been classified as a possible human carcinogen (group 2B) by the International Agency for Research on Cancer (IARC) [152][153][154]. Preserved meats and cheeses are the main contributors to dietary exposure to OTA in several European countries [154]. ...
... The most important AFs are B1, B2, G1 and G2. These mycotoxins are carcinogenic (Group 1) and mutagenic for animals and humans according to the IARC [152]. ...
Article
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Ripened foods of animal origin comprise meat products and dairy products, being transformed by the wild microbiota which populates the raw materials, generating highly appreciated products over the world. Together with this beneficial microbiota, both pathogenic and toxigenic microorganisms such as Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, Clostridium botulinum, Escherichia coli, Candida spp., Penicillium spp. and Aspergillus spp., can contaminate these products and pose a risk for the consumers. Thus, effective strategies to hamper these hazards are required. Additionally, consumer demand for clean label products is increasing. Therefore, the manufacturing sector is seeking new efficient, natural, low-environmental impact and easy to apply strategies to counteract these microorganisms. This review gathers different approaches to maximize food safety and discusses the possibility of their being applied or the necessity of new evidence, mainly for validation in the manufacturing product and its sensory impact, before being implemented as preventative measures in the Hazard Analysis and Critical Control Point programs.
... Benzene and 1,3-butadiene have attracted particular attention because of their potential adverse effects on human health. The IARC recently reconfirmed that benzene is carcinogenic, may cause acute myeloid leukaemia, and is likely to cause other leukaemia subtypes and lymphoid neoplasms in humans (IARC, 2012). The IARC also concluded that 1,3-butadiene is carcinogenic and may cause cancer of the haematolymphatic organs (IARC, 2012). ...
... The IARC recently reconfirmed that benzene is carcinogenic, may cause acute myeloid leukaemia, and is likely to cause other leukaemia subtypes and lymphoid neoplasms in humans (IARC, 2012). The IARC also concluded that 1,3-butadiene is carcinogenic and may cause cancer of the haematolymphatic organs (IARC, 2012). ...
Article
Aims: The main aim of this study was to assess dermal exposure to polycyclic aromatic hydrocarbons (PAHs) and airway exposure to PAHs, volatile organic compounds (VOCs; benzene and 1,3-butadiene), and particles among firefighters (FFs) and police forensic investigators (PFIs) in Sweden. Methods: Active (pump with a filter and sorbent tube) and passive (polyurethane foam -cyl and perkin elmer carbopack-tube) personal air sampling and dermal tape stripping (wrist and collar bone) were performed on seven FF team leaders during training fires and nine PFIs investigating the aftermath of live fire events. In addition, passive personal air sampling was performed on eight FF team leaders during live emergency fires. PAHs and VOCs were analysed using high-resolution gas chromatography low-resolution mass spectrometry. The mass concentration of total dust (particles) was determined using standard gravimetric methods. Results: The air samples showed that the exposure to PAHs, benzene, 1,3-butadiene, and particles was below Swedish occupational exposure limits (OELs). Naphthalene was the predominant PAH in all air samples. Benzene and 1,3-butadiene were more abundant in live emergency fires, which caused higher exposures than the other studied situations. Both gaseous- and particle-associated PAHs were present on skin. The wrists seemed to be less well protected than the collarbone area. Conclusions: FFs and PFIs are exposed to several hazardous compounds during their work. Air exposures varied considerably between working scenarios. The observed exposures were substantially higher than urban background levels but well below Swedish OELs. The measured dermal PAH exposures were comparable to previously reported doses for US FFs but lower than the exposures reported for Swedish chimney sweeps.
... Low-risk mucosal HPVs like HPV-6 and HPV-11 commonly result in genital warts (condyloma acuminate), while high-risk HPVs lead to squamous intraepithelial lesions that may progress to invasive squamous cell carcinoma. The majority of human cervical cancers are attributed to high-risk HPV infections, with HPV-16 being the most prevalent, followed by HPV-18, HPV-31, and others 16,17 . ...
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Carcinogens, which induce mutations in DNA or chromosomes, encompass a wide range of genotoxins including high-energy radiation (e.g., UV light), chemical pollutants (e.g., tobacco smoke, alcohol), and biological agents (e.g., oncogenic viruses). Carcinogenesis arises from the accumulation of genetic damage, with malignancies displaying heightened immunogenicity due to mutational load. Carcinogens also provoke immune responses and epigenetic changes, leading to genomic instability and cancer progression. These agents are classified into chemicals, radiation (ionizing and non-ionizing), and biological entities. Industrialization has saturated the environment with genotoxic substances, increasing genetic disorders. Daily exposure to genotoxic substances through manufacturing and consumption exacerbates this issue. Key genotoxic chemicals include polycyclic aromatic hydrocarbons, aromatic amines, nitrosamines, alkylating agents, formaldehyde, arsenic, cadmium, benzene, and acrylamide. Natural chemicals like benzo(a)pyrene and arsenic are also genotoxic, with arsenic known for inducing apoptosis via reactive oxygen species (ROS). Workers in industries such as pesticides, sulphur, agrochemicals, coal mining, and gasoline are at high risk due to occupational exposure. Understanding carcinogens is crucial for assessing cancer risk and implementing prevention strategies. Lifestyle factors like diet, smoking, alcohol, and medications also contribute to genotoxicity and cancer risk. This chapter underscores the significant impact of genotoxic substances on human health.
... Aflatoxin poisoning can occur directly, via skin contact with contaminated field crops and stored produce, but more commonly through ingestion, either of contaminated crop products or secondary products, such as milk, from animals that have consumed contaminated feed. Aflatoxin poisoning is implicated in delayed development in children and severe liver damage resulting in liver cancer 3 . Aspergillus flavus is a major source of AFB 1 . ...
Article
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Aflatoxin contamination caused by colonization of maize by Aspergillus flavus continues to pose a major human and livestock health hazard in the food chain. Increasing attention has been focused on the development of models to predict risk and to identify effective intervention strategies. Most risk prediction models have focused on elucidating weather and site variables on the pre-harvest dynamics of A. flavus growth and aflatoxin production. However fungal growth and toxin accumulation continue to occur after harvest, especially in countries where storage conditions are limited by logistical and cost constraints. In this paper, building on previous work, we introduce and test an integrated meteorology-driven epidemiological model that covers the entire supply chain from planting to delivery. We parameterise the model using approximate Bayesian computation with monthly time-series data over six years for contamination levels of aflatoxin in daily shipments received from up to three sourcing regions at a high-volume maize processing plant in South Central India. The time series for aflatoxin levels from the parameterised model successfully replicated the overall profile, scale and variance of the historical aflatoxin datasets used for fitting and validation. We use the model to illustrate the dynamics of A. flavus growth and aflatoxin production during the pre- and post-harvest phases in different sourcing regions, in short-term predictions to inform decision making about sourcing supplies and to compare intervention strategies to reduce the risks of aflatoxin contamination.
... 1,3-Butadiene is a colorless gas with a mild gasoline-like odor and an odor threshold value of 0.45 ppm [7]. There is a strong association between occupational exposure to 1,3-butadiene and the occurrence of cancers of hemolymphatic organs, mainly leukemia [3,8,9]. The International Agency for Research on Cancer (IARC) has identified this chemical agent as carcinogenic to humans by inhalation and has classified 1,3-Butadiene in group 1 of carcinogens [10]. ...
Article
Background: Workplace violence is an important event that affects the safety of healthcare employees, and diagnosing it in hospitals is an immediate occupational concern. Objective: The present study was conducted to investigate general health and the prevalence of occupational violence and to predict its consequences among nurses and paramedics as the main body in medical settings. Methods: This cross-sectional study was performed in 2020 in a selected hospital in Tehran, Iran. A total of 208 healthcare workers participated in the study. To study general health, exposure to workplace violence, job burnout, and productivity, the general health questionnaire (GHQ), the workplace violence questionnaire, the Maslach burnout questionnaire, and the workforce productivity questionnaire were provided to healthcare workers, respectively. Then, a multiple linear regression model was used to predict violence and its consequences. Results: The results revealed that 34.1% of the participants have psychological disorders, and 74.5% have experienced one type of violence in their workplace at least once during the past year. The multiple linear regression model results indicated that workplace violence prevalence proved the ability to predict the increase in burnout and decrease in job productivity. Conclusion: Exposure to violence in the workplace significantly increases the risk of mental disorders associated with the risk of mental illness. Therefore, managing exposure to violence in the workplace is a practical step in improving general and mental health and ultimately increasing job productivity in medical settings.
... Formalin, an aqueous form of formaldehyde, contains 37% by weight or 40% by volume of formaldehyde gas in water. According to the International Agency for Research on Cancer (IARC, 2012) [10] , formaldehyde is classified as Group 1 carcinogen, primarily based on its association with nasopharyngeal cancer. Chronic exposure to formaldehyde has been reported to have longterm health effects such as pharyngeal congestion, chronic phayrgitis, loss of olfactory functioning, lacrimation and cornea disorder, heartburn, and lethargy (Dai and Bao, 1999) [6] . ...
Article
The free and bound formaldehyde concentration in six commercially important fishes from five major fish markets of Tamil Nadu, India were analyzed. The highest concentration of free and bound formaldehyde (9.8 and 6.45 mg/kg) was observed in Sphyraena barracuda and the lowest (0.8 and 0.5 mg/kg) concentration was observed in Lethrinus lentjan. Storage of S. barracuda in ice indicated a significant (p<0.05) increase in formaldehyde concentration after 3 days. S. barracuda stored in a deep freezer (-20 °C) for 30 days showed that there was no significant (p>0.05) increase in formaldehyde concentration upto 15 days after which there was a significant increase upto 30 days. S. barracuda spiked with various concentration of formaldehyde followed by boiling for 15 min indicated no significant reduction (p>0.05) in formaldehyde concentration. Formaldehyde treated S. barracuda washed after different time intervals indicated that washing reduces upto 41 to 60% of treated formaldehyde.
... water activity, a w ) which can allow certain xerophilic or xerotolerant genera such as Aspergillus and Penicillium to colonise the substrate and produce SMs. The most important toxic SMs in maize are aflatoxins (class 1 carcinogen [8]), fumonisins and ochratoxin A. There is significant knowledge about these toxic SMs produced by species such as Aspergillus section Flavi, Fusarium section Liseola and Aspergillus section Circumdati species, respectively. The most important environmental factors which influence the ability of the naturally contaminating mycobiota to colonise the maize post-harvest are temperature (T) and m.c. or a w . ...
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There is interest in understanding the relationship between naturally contaminated commodities and the potential for the production of different useful and toxic secondary metabolites (SMs). This study examined the impact of interacting abiotic stress parameters of water availability and temperature of stored naturally contaminated maize on the SM production profiles. Thus, the effect of steady-state storage water activity (aw; 0.80–0.95) and temperature (20–35 °C) conditions on SM production patterns in naturally contaminated maize was examined. The samples were analysed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) to evaluate (a) the total number of known SMs, (b) their concentrations, and (c) changes under two-way interacting environmental stress conditions. A total of 151 metabolites were quantified. These included those produced by species of the Aspergillus, Fusarium and Penicillium genera and other unspecified ones by other fungi or bacteria. There were significant differences in the numbers of SMs produced under different sets of interacting environmental conditions. The highest total number of SMs (80+) were present in maize stored at 20–25 °C and 0.95 aw. In addition, there was a gradation of SM production with the least number of SMs (20–30) produced under the driest conditions of 0.80 aw at 20–30 °C. The only exception was at 35 °C, where different production patterns occurred. There were a total of 38 Aspergillus-related SMs, with most detected at >0.85 aw, regardless of the temperature in the 50–500 ng/g range. For Fusarium-related SMs, the pattern was different, with approx. 10–12 SMs detected under all aw x temperature conditions with >50% produced at 500 ng/g. A total of 40–45 Penicillium-related SMs (50–500 ng/g) were detected in the stored maize but predominantly at 20–25 °C and 0.95 aw. Fewer numbers of SMs were found under marginal interacting abiotic stress storage conditions in naturally contaminated maize. There were approx. eight other known fungal SM present, predominantly in low concentrations (<50 ng/g), regardless of interacting abiotic conditions. Other unspecified SMs present consisted of <20 in low concentrations. The effect of interacting abiotic stress factors for the production of different suites of SMs to take account of the different ecological niches of fungal genera may be beneficial for identifying biotechnologically useful SMs.
... 1,3-Butadiene is a colorless gas with a mild gasoline-like odor and an odor threshold value of 0.45 ppm [7]. There is a strong association between occupational exposure to 1,3-butadiene and the occurrence of cancers of hemolymphatic organs, mainly leukemia [3,8,9]. The International Agency for Research on Cancer (IARC) has identified this chemical agent as carcinogenic to humans by inhalation and has classified 1,3-Butadiene in group 1 of carcinogens [10]. ...
Article
Purpose: This study aimed to carcinogenic and health risk assessment of respiratory exposure to acrylonitrile, 1,3-butadiene, and styrene in the petrochemical industry. Materials and methods: This cross-sectional study was conducted in a petrochemical plant producing acrylonitrile, butadiene, and styrene (ABS) copolymers. Respiratory exposure with acrylonitrile, 1,3-butadiene and styrene was measured using methods No. 1604, 1024, and 1501 of the National Institute of Occupational Safety and Health, respectively. The US Environmental Protection Agency method was used to assess carcinogenic and health risks. Results: The average occupational exposure to acrylonitrile, 1,3-butadiene, and styrene was 560.82 μg. m-3 for 1,3-butadiene, 122.8 μg. m-3 for acrylonitrile and 1.92 μg. m-3 for styrene. The average lifetime cancer risk (LCR) in the present study was 2.71 ×10-3 for 1,3-butadiene, 2.1 ×10-3 for acrylonitrile, and 6.6 for styrene. Also, the mean non-cancer risk (HQ) among all participants for 1,3-butadiene, acrylonitrile, and styrene was 4.04 ± 6.93, 10.82 ± 14.76, and 0.19 ± 0.11, respectively. Conclusion: The values of carcinogenic and health risks in the majority of the subjects were within the unacceptable risk levels due to exposure to 1,3-butadiene, acrylonitrile, and styrene vapors. Hence, corrective actions are required to protect the workers from non-cancer and cancer risks.
... The latter two are considered to have a greater risk of adverse health effects, either due to acute or chronic exposure (Table 3). For example, benzene is recognized as a Group-1 carcinogen (IARC, 2012). The working day in the manufacture of shoes is approximately eight hours a day. ...
Article
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The social and economic dynamics in Ticul municipality in Yucatán is based on labor-intensive and low-tech pottery and shoe manufacturing, contributing thereby 55% of the municipality’s total gross production. Despite its economic importance and employment, there are no environmental policies focused on these economic activities in the community, which has led to environmental, social, health problems in children and concerns of hazardous waste. The article’s objective is to document a successful case of a plastics recycler through a mixed-methods approach that allows identifying a critical path for promoting activities in favor of a circular economy and the generation of green jobs in the municipality. The result was higher than 70 per cent in the green employment index. The green employment generated in the plastic recycler in Ticul, Yucatán is considered to be an adequate performance in decent work. Even though the work carried out in the recycler cannot mitigate the waste and toxic substances generated by the manufacture of shoes, this study enables us to conclude that the promotion of such recycling activities facilitates the employment of a more significant number of people to jobs with less precariousness and exposure to toxic substances, therefore, ensuring their better occupational health, as well as reducing negative impacts on the environment.
... AFs have been associated with numerous human and animal diseases such as immunosuppression, mutagenicity, genotoxicity, and hepatocelular carcinoma (Atanda et al., 2011;Abdel-Wahhab et al., 2012a). Aflatoxin B 1 (AFB 1 ) is the strongest known hepato carcinogen and is classified as a category 1A carcinogen by the International Agency for Research on Cancer (IARC, 2012). Its carcinogenicity is exerted through its metabolic activation to the reactive AFB 1 8, 9-exoepoxide by cytochrome P 450 monooxygenases (Chu et al., 2017). ...
Article
This study aimed to determine the bioactive compounds of Bacillus sp. MERNA97 extract and to evaluate their efficacy against the oxidative damage, genotoxicity, chromosomal aberration and DNA fragmentation in rats treated with AFB1. Sixty male Sprague-Dawley rats were divided into 6 groups and treated for 6 weeks and included the control group, AFB1-treated group (80 μg/kg b. w), the groups treated with Bacillus extract (BE) at low (2 mg/kg b.w) or high (4 mg/kg b.w) dose and the groups treated with AFB1 plus BE at the two doses. Blood and tissues samples were collected for different assays. The GC-MS results revealed the isolation of 44 compounds belong to different classes. The in vivo results showed that AFB1 disturbs all the biochemical parameters, oxidative stress markers, cytokines gene expression chromosomal aberration and DNA fragmentation along with the histological changes in the liver tissue. BE at the two tested doses induced a significant improvement in all parameters tested and the histological picture in a dose dependent manner. It could be concluded that the extract of Bacillus sp. MERNA97 isolated from the marine environment in the Red Sea is a promise as a source of novel compounds with therapeutically benefits.
... Benzene is a common occupational solvent that has had used in multiple industries, including rubber tire manufacturing and the printing industry. The International Agency for Research on Cancer (IARC) has classified benzene as a Group 1 human carcinogen since 1979, based primarily on sufficient evidence that it causes acute myeloid leukemia (IARC, 2012). IARC's most recent evaluation of benzene in 2017 reaffirmed previous conclusions that there was limited evidence of a positive association with risk of NHL, including chronic lymphocytic leukemia subtype (Loomis et al., 2017). ...
Article
Objectives: Occupational exposures in population-based case-control studies are increasingly being assessed using decision rules that link participants' responses to occupational questionnaires to exposure estimates. We used a hierarchical process that incorporated decision rules and job-by-job expert review to assign occupational benzene exposure estimates in a US population-based case-control study of non-Hodgkin lymphoma. Methods: We conducted a literature review to identify scenarios in which occupational benzene exposure has occurred, which we grouped into 12 categories of benzene exposure sources. For each source category, we then developed decision rules for assessing probability (ordinal scale based on the likelihood of exposure > 0.02 ppm), frequency (proportion of work time exposed), and intensity of exposure (in ppm). The rules used the participants' occupational history responses and, for a subset of jobs, responses to job- and industry-specific modules. For probability and frequency, we used a hierarchical assignment procedure that prioritized subject-specific module information when available. Next, we derived job-group medians from the module responses to assign estimates to jobs with only occupational history responses. Last, we used job-by-job expert review to assign estimates when job-group medians were not available or when the decision rules identified possible heterogeneous or rare exposure scenarios. For intensity, we developed separate estimates for each benzene source category that were based on published measurement data whenever possible. Frequency and intensity annual source-specific estimates were assigned only for those jobs assigned ≥75% probability of exposure. Annual source-specific concentrations (intensity × frequency) were summed to obtain a total annual benzene concentration for each job. Results: Of the 8827 jobs reported by participants, 8% required expert review for one or more source categories. Overall, 287 (3.3%) jobs were assigned ≥75% probability of exposure from any benzene source category. The source categories most commonly assigned ≥75% probability of exposure were gasoline and degreasing. The median total annual benzene concentration among jobs assigned ≥75% probability was 0.11 ppm (interquartile range: 0.06-0.55). The highest source-specific median annual concentrations were observed for ink and printing (2.3 and 1.2 ppm, respectively). Conclusions: The applied framework captures some subject-specific variability in work tasks, provides transparency to the exposure decision process, and facilitates future sensitivity analyses. The developed decision rules can be used as a starting point by other researchers to assess occupational benzene exposure in future population-based studies.
... Simultaneously, gas phase pyrolysis occurs. As a result, this process produces by-products, including Polycyclic Aromatic Hydrocarbons (PAH) which may contain carcinogenic substances such as benzo[a]pyrene (BaP) [3]. These by-products condense in cold zones in the reactor, mainly exhaust pipes [4]. ...
Article
The aim of this study was to understand the formation of PAHs (Polycyclic Aromatic Hydrocarbons) during acetylene pyrolysis. Experiments were carried out with a jet-stirred-reactor in laboratory conditions similar to those used in industrial low-pressure gas carburizing processes (1173 K and 8 kPa). The influence of residence time was studied. At the outlet from the reaction zone, products of pyrolysis were analyzed by gas chromatography (mass detector). A detailed kinetic model was used to describe PAH formation and to validate experimental findings. Differences were found between the experiments and the kinetic model. Several explanations are presented such as a lack of mixing within the reactor. To explain why the reactor's hydrodynamic characteristics deviate from the perfectly stirred assumption under several operating conditions, such as low-pressure and high temperature, CFD calculations were performed to determine the Residence Time Distribution (RTD) of the gas phase. This deviation is particularly linked to the pressure in the chamber which was not taken into account when constructing the jet-stirred-reactor over the last fifty years.
... Simultaneously, gas phase pyrolysis occurs. As a result, the by-products to this process include Polycyclic Aromatic Hydrocarbons (PAH), many of which are carcinogenic substances, such as benzo[a]pyrene (BaP) (IARC, 2012). These by-products condense as soot or tar mainly in exhaust pipes or cold zones in the reactor (Champmartin et al., 2017). ...
Article
Low-pressure gas carburizing is used to harden steel, it has been shown to be a source of considerable PAH (Polycyclic Aromatic Hydrocarbon) pollution. Some PAH, like benzo[a]pyrene, are carcinogenic, and activities such as furnace maintenance and cleaning operations may thus represent a risk to workers. Occupational exposure during these operations should therefore be reduced. Benzene is a specific chemical marker of PAH, and the aim of the study was to understand its formation. Acetylene pyrolysis was experimentally performed in a jet-stirred-reactor in the laboratory, in conditions close to those encountered in industrial processes (1173 K and 8 kPa). Products of pyrolysis were analyzed by gas chromatography (TCD, FID) at the outlet from the reaction zone. The influence of residence time in the reactor was studied. A detailed kinetic model assuming an ideal continuous stirred tank reactor was used to describe the formation of chemical compounds and validate experimental data. CFD simulations were performed to characterize the reactor's hydrodynamics by applying the theory of the free jet. They allowed putting forward one explanation to understand the deviation between experiments and the kinetic model.
Chapter
Workers are exposed to carcinogens and carcinogenic exposure circumstances, as well as to many other agents considered probably, possibly, or reasonably anticipated to be human carcinogens. Covered herein are occupational carcinogens: chemicals, uncharacterized exposure circumstances, and occupations/workplaces known or suspected to cause cancer in workers, and agents causing cancers in animal bioassays, which are proven predictive for human cancers. Importantly, individuals differ in susceptibility for developing cancer due to exposure to a carcinogenic substance; factors influencing cancer outcomes include exposure circumstances, genetic differences, lifestyle, health condition, age, and gender. Identification of agents as carcinogens is based on information from epidemiological studies, long‐term animal studies, in vitro and in vivo evaluations, and assessments of mechanistic data and structure‐activity relationships. Various agencies, such as IARC, NTP, U.S. EPA, CalEPA, and others have developed classification schemes that categorize potential carcinogenicity of environmental and industrial agents in humans based on strength‐of‐evidence from human studies, animal studies, and mechanistic information. Categorizations formulated by authoritative bodies serve as the initial basis for standard's settings and regulatory actions. Several health and safety laws have been promulgated to protect workers from harmful effects of hazardous agents in the workplace. Risk characterization provides an integrative summary of available and relevant information on hazard identification, exposure assessment, and dose‐response relationships that have been used to estimate potential human cancer risks under various exposure circumstances. This information serves as the basis for risk management decisions on the extent to which workers' exposures to hazardous agents should be controlled. Likewise reducing or eliminating exposures to known and suspected carcinogens will reduce or prevent the incidences of occupational cancers. The World Health Organization reports occupational carcinogens are responsible for ∼152,000 cancer deaths per year and cancer prevention is essential because ∼40% of all cancer deaths can be prevented.
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Food industrial bacterial cells eliminate aflatoxin M1 (AFM1) at different ratios. The study aimed to investigate the effect of AFM1 on probiotic industrial bacteria ( Lactococcus lactis ssp. lactis R703, Bifidobacterium animalis ssp . lactis BB12, and L. paracasei subsp . paracasei 431) and evaluating their AFM1 binding ability in naturally contaminated milk. The growth of the R703 strain was affected by AFM1 at 1.47 μg L ⁻¹ concentration. Peptidoglycan (PG) cell wall fractions of R703 and BB12 bound a significant amount of AFM1 from naturally contaminated milk under one-hour treatment, while L. paracasei 431 was not effective. PG was better absorbent for AFM1 than viable cells of BB12, while the difference was insignificant for the R703 strain. Increasing the time did not significantly change the mycotoxin binding of BB12, while for R703 PG the absorption seemed reversible. BB12 PG needs further analysis for biotechnological application in dairy products.
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The aim of this study was to determine the microbial diversity and mycotoxin profile of artisanal infant flours commonly vended in public healthcare centres and retail markets in Côte d’Ivoire. Thus, maize, millet, sorghum, soya and multigrain (mix of different cereals) flour samples collected from different localities were first, analysed for nutritional composition, then for microbial communities using high-throughput sequencing and for mycotoxins through UHPLC-MS/MS method. Firmicutes was the most abundant bacterial phylum and the dominant genera were Weissella, Staphylococcus, Pediococcus. Potential pathogenic genera such as Bacillus, Enterobacter, Acinetobacter and Burkholderia were also found. The fungal community was composed of two dominant phyla (Ascomycota and Basidiomycota) and 31 genera with > 0.1% relative abundance. In samples from public healthcare centres, Candida, Hyphopichia, Trichosporon, and Cyberlindnera were the most dominant genera according to the flour type while in samples from retail markets, they were Cyberlindnera, Clavispora, Nakaseomyces, Aureobasidium and Candida. Possible toxigenic genera Fusarium and Aspergillus were also detected. Aflatoxin B1 (AFB1), Ochractoxin (OTA), Fumonisin B1 (FB1) and B2 (FB2) were the mycotoxins found in the analysed flours. AFB1 was detected in 100% of maize (range 1.2–120.5 µg/kg; mean: 44.2 µg/kg) and 50–83.3% of millet flours (range 0.2–31.5 µg/kg; mean: 31.5 µg/kg). Its level in all maize and rice flour samples exceeded EU standard (0.1 µg/kg). For OTA and fumonisins, millet and maize flours showed the highest levels of sample exceeding the EU standard. Thus, artisanal infant flours marketed in Côte d’Ivoire, mainly maize and rice flours, although containing potentially beneficial bacteria, represent potential health risks for children.
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Preparing of calibration curves are critical steps for accurate quantitative LC-MS bioanalysis. Traditional multi-sample external calibration curve (MSCC) is labor-intensive and prone to error. In this study, a novel strategy of one sample multi-point calibration curve (OSCC) using multiple isotopologue reaction monitoring (MIRM) was proposed and validated using LC-MS for the quantitation of six aflatoxins in milk and oat-based milk samples. The developed MIRM-OSCC methodology is comprehensively validated and the results indicated that the established method exhibits good performance in selectivity, sensitivity, accuracy and precision. Furthermore, the OSCC could realize sample dilution by monitoring the MIRM channel with less intensity for samples beyond the upper limit of quantification, without the need of sample dilution, which improves the assay throughput. Considering the advantages of excluding the MSCC preparation and sample dilution in OSCC, this strategy can be widely applied in various fields such as drugs, food safety and environmental analysis.
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The rational design of methodologies to control the neoformed compounds occurrence (NFCs), such as acrylamide and hydroxymethylfurfural (HMF) in roasted coffee, must consider the preservation of the bioactive compounds contained in this beverage. The aim of this work was to evaluate the integrated effect of yeast inoculation during the fermentation stage and the modification of roasting parameters on the final concentrations of NFCs and bioactive compounds of roasted coffee. A completely randomized factorial design was used to evaluate the effect of yeast inoculation (with and without inoculation), roasting temperature (150, 180 and 210 °C) and roast degree (medium, dark) on the (i) physicochemical characteristics (volume change, mass loss, water activity, non-enzymatic browning index, antioxidant capacity, total polyphenols, chlorogenic acid and caffeine) as well as HMF and acrylamide levels of roasted coffee. Response variables were analyzed separately by ANOVA and clustering of treatments was explored by PCA. Yeast inoculation did not significantly (p > 0.05) affect volume change, mass loss, antioxidant capacity, total polyphenols content, and caffeine contents. The interaction of evaluated factors significantly decreased (p < 0.05) the acrylamide and HMF contents of roasted coffee (43 % and 56.0 %, respectively). Based on PCA grouping the best treatments were medium roast at 210 °C (inoculated and uninoculated) and at 180 °C (inoculated). Under these conditions it is possible to produce a roasted coffee mitigated in neo formed contaminants that present the physicochemical properties of original product.
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Mycotoxin contamination of food and beverages is a common food safety issue. With the high demand for analyses related to quality control of these products, there is an increasing search for the development of methods with low cost and low consumption of reagents but adequate to determine low levels of concentration in a selective or specific way. However, due to the physicochemical particularities of mycotoxins, the analytical process for the detection of this toxin is complex, requiring different detection systems for the different classes studied. In this sense, electrochemical methods have been applied to mycotoxin determination with remarkable sensitivity and selectivity, through the use of several working electrodes developed from different types of substrates and modification techniques. Therefore, this review paper focuses on the application of electrochemical techniques in the determination of several mycotoxins, as well as also addresses general aspects of this class of compounds and the importance of their determinations.
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The level and distribution of Polycyclic Aromatic Hydrocarbon (PAHs) in soil, fruit, and leaf from within automobile repair workshops in Nsukka metropolis was assessed. The PAHs concentrations were evaluated using Gas Chromatography-Mass Spectrophotometer (GC-MS). The health risk was assessed using incremental life cancer risk (ILCR) and mutagenic effect and the possible sources of the PAHs were estimated by the diagnostic ratio. The results showed that the concentrations of the PAHs in soil, fruit, and leaf ranged from 0.003 to 0.564, 0.011 to 0.070, and 0.020 to 0.120 mg/kg, respectively. The mean PAHs concentration for soil, fruit, and leaf are 0.229842, 0.034059, and 0.043091 mg/kg, respectively. The TEQs were generally within the acceptable limit stipulated by Agency for Toxic Substances Disease Registry-ATSDR (100 mg/kg) for non-pollution and low toxicity. The incremental lifetime cancer risk (ILCR) for the seven prominent carcinogenic PAHS indicated that Benzo(a)pyrene and Dibenz(a,h)anthrance, being the most toxic were above the acceptable limit of 1 Â 10 À4 showing possible carcinogenic effects to humans with children being the most vulnerable. Although the concentration of PAHs in this study is lower than many similar cases, they have a high risk of carcinogenesis. In contrast, the Mutagenic Equivalent Quotient (MEQ) values were generally within the acceptable value. Benzo(a)pyrene and Dibenz(a,h)anthrance were the most contributors signifying possible alternation/modification of DNA in humans. The Diagnostic ratio showed that pyrogenic combustions could be the main sources of PAHs in the studied area. Therefore, it is evident that Nsukka automobile repair area is gradually being contaminated with PAHs. ARTICLE HISTORY
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Humans are potentially exposed to a large amount of chemicals present in the environment and in the workplace. In the European Human Biomonitoring initiative (Human Biomonitoring for the European Union = HBM4EU), acrylamide, mycotoxins (aflatoxin B1, deoxynivalenol, fumonisin B1), diisocyanates (4,4’-methylenediphenyl diisocyanate, 2,4- and 2,6-toluene diisocyanate), and pyrethroids were included among the prioritized chemicals of concern for human health. For the present literature review, the analytical methods used in worldwide biomonitoring studies for these compounds were collected and presented in comprehensive tables, including the following parameter: determined biomarker, matrix, sample amount, work-up procedure, available laboratory quality assurance and quality assessment information, analytical techniques, and limit of detection. Based on the data presented in these tables, the most suitable methods were recommended. According to the paradigm of biomonitoring, the information about two different biomarkers of exposure was evaluated: a) internal dose = parent compounds and metabolites in urine and blood; and b) the biologically effective = dose measured as blood protein adducts. Urine was the preferred matrix used for deoxynivalenol, fumonisin B1, and pyrethroids (biomarkers of internal dose). Markers of the biological effective dose were determined as hemoglobin adducts for diisocyanates and acrylamide, and as serum-albumin-adducts of aflatoxin B1 and diisocyanates. The analyses and quantitation of the protein adducts in blood or the metabolites in urine were mostly performed with LC-MS/MS or GC-MS in the presence of isotope-labeled internal standards. This review also addresses the critical aspects of the application, use and selection of biomarkers. For future biomonitoring studies, a more comprehensive approach is discussed to broaden the selection of compounds.
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Aflatoxins are the highly toxic secondary metabolites of fungal species of Aspergillus origin, particularly of Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are present in a number of food commodities, especially cereals, spices, dry fruits, and milk and milk products. Aflatoxins are classified as group 1 category carcinogenic compound by the International Agency for Research on Cancer (IARC) and are also hepatotoxic, immunosuppressant, growth retardant, teratogenic, and mutagenic. Based on the severe health implications of aflatoxins, countries across the world have established maximum permissible limits/regulations for aflatoxins in different foodstuffs. Prevalence of aflatoxins in a number of food commodities and its highly toxic nature have compelled the researchers across the world to explore safe, reliable, and commercially implementable methods for the removal/degradation of aflatoxins.
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Microplastic (MP) debris is considered as a potentially hazardous material. It is omnipresent in our environment, and evidence that MP is also abundant in the atmosphere is increasing. Consequently, the inhalation of these particles is a significant exposure route to humans. Concerns about potential effects of airborne MP on human health are rising. However, currently, there are not enough studies on the putative toxicity of airborne MP to adequately assess its impact on human health. Therefore, we examined potential drivers of airborne MP toxicity. Physicochemical properties like size, shape, ζ-potential, adsorbed molecules and pathogens, and the MP’s bio-persistence have been proposed as possible drivers of MP toxicity. Since their role in MP toxicity is largely unknown, we reviewed the literature on toxicologically well-studied non-plastic airborne microparticles (asbestos, silica, soot, wood, cotton, hay). We aimed to link the observed health effects and toxicology of these microparticles to the abovementioned properties. By comparing this information with studies on the effects of airborne MP, we analyzed possible mechanisms of airborne MP toxicity. Thus, we provide a basis for a mechanistic understanding of airborne MP toxicity. This may enable the assessment of risks associated with airborne MP pollution, facilitating effective policymaking and product design.
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Formaldehyde mainly emitted from wood adhesives, finishing materials, paint for furniture represents, together with wood dust, a potential carcinogenic risk for wood workers. Aims of this multidisciplinary study are to investigate the possibility of replacing urea-formaldehyde (UF) adhesives in the wood industry with organic and/or inorganic-based glues to obtain a final less toxic product and to evaluate the potential toxicity of wood glued with such new adhesives. For this purpose we selected poplar wood to test an organic new adhesive HBP (Hemp Based Protein), a mixture of hemp flour and cross-linker PAE (polyaminoamide epichlorohydrin), and spruce wood to test an inorganic adhesive geopolymer K-PSS (potassium-polysiloxosialate) plus polyvinyl acetate. For the poplar wood, we also used a commercial panel glued with UF for comparison. We reproduced occupational inhalation exposure during sawing activities of mentioned woods, collected and characterized the wood dusts emitted during sawing and evaluated in vitro their potential cyto-genotoxic and inflammatory effects. We used human lung cells (A549) exposed for 24 h to 20 and 100 µg/mL of collected PM2.5 wood dust. We found that both the new adhesives wood dusts induced a slightly higher apoptotic effect than untreated natural wood dusts particularly in spruce wood. Only geopolymer K-PSS wood dust induced membrane damage at the highest concentration and direct and oxidative DNA damage that could be explained by the different chemical composition and the lower particle sizes in respect to organic HBP adhesive wood dust. We found slight induction of IL6 release, not influenced by K-PSS treatment, at the highest concentration in spruce wood. For poplar wood, IL-6 and IL-8 induction was found particularly for untreated and UF-treated wood at the highest concentration, where hemp adhesive treatment induced lower inflammation while at lower concentration similar slight cytokine induction was found for all tested wood dusts. This preliminary study shows that natural adhesives used to replace UF adhesives represent an interesting alternative, particularly the organic hemp-based adhesive showing very low toxicity.
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Objectives Inappropriate processing and disposal of electronic waste (e-waste) expose workers and surrounding populations to hazardous chemicals, including clastogens and aneugens. Recently, considerable literature has grown around e-waste recycling, associated chemical exposures and intermediate health outcomes, including DNA damage. Micronuclei (MN) frequency has been widely used as a biomarker to investigate DNA damage in human populations exposed to genotoxic agents. We conducted a systematic review of published studies to assess DNA damage in e-waste-exposed populations and performed a meta-analysis to evaluate the association between e-waste exposure and DNA damage. Methods This systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement checklist. Articles published in English from January 2000 through December 2020 investigating the associations between e-waste exposure and DNA damage were retrieved from the following three major databases: MEDLINE, ProQuest, and Scopus. Studies that reported the use of MN assay as a biomarker of DNA damage were included for meta-analysis. Studies that also reported other DNA damage biomarkers such as chromosomal aberrations, comet assay biomarkers, 8-hydroxy-2′-deoxyguanosine (8-OHdG), telomere length, apoptosis rate were reported using narrative synthesis. Results A total of 20 publications were included in this review, of which seven studies were within the occupational setting, and the remaining 13 studies were ecological studies. The review found six biomarkers of DNA damage (micronuclei, comets assay parameters (tail length, % tail DNA, tail moment, and olive tail moment), 8-OHdG, telomere length, apoptosis rate and chromosomal aberrations) which were assessed using seven different biological matrices (buccal cells, blood, umbilical cord blood, placenta, urine and semen). Most studies showed elevated levels of DNA damage biomarkers among e-waste exposed populations than in control populations. The most commonly used biomarkers were micronuclei frequency (n=9) in peripheral blood lymphocytes or buccal cells and 8-OHdG (n=7) in urine. The results of the meta-analysis showed that electronic waste recycling has contributed to an increased risk of DNA damage measured using MN frequency with a pooled estimate of the standardized mean difference (SMD) of 2.30 (95% CI: 1.36, 3.24, p<0.001) based on 865 participants. Conclusions Taken together, evidence from this systematic review with meta-analysis suggest that occupational and non-occupational exposure to e-waste processing is associated with increased risk of DNA damage measured through MN assay and other types of DNA damage biomarkers. However, more studies from other developing countries in Africa, Latin America, and South Asia are needed to confirm and increase these results’ generalizability.
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Local accumulation of xenobiotics in human and animal tissues may cause adverse effects. Large differences in their concentrations may exist between individual cell types, often due to the expression of specific uptake and export carriers. Here we established a two-photon microscopy-based technique for spatio-temporal detection of the distribution of mycotoxins in intact kidneys and livers of anesthetized mice with subcellular resolution. The mycotoxins ochratoxin A (OTA, 10 mg/kg b.w.) and aflatoxin B 1 (AFB 1 , 1.5 mg/kg b.w.), which both show blue auto-fluorescence, were analyzed after intravenous bolus injections. Within seconds after administration, OTA was filtered by glomeruli, and enriched in distal tubular epithelial cells (dTEC). A striking feature of AFB 1 toxicokinetics was its very rapid uptake from sinusoidal blood into hepatocytes ( t 1/2 ~ 4 min) and excretion into bile canaliculi. Interestingly, AFB 1 was enriched in the nuclei of hepatocytes with zonal differences in clearance. In the cytoplasm of pericentral hepatocytes, the half-life ( t 1/2 ~ 63 min) was much longer compared to periportal hepatocytes of the same lobules ( t 1/2 ~ 9 min). In addition, nuclear AFB 1 from periportal hepatocytes cleared faster compared to the pericentral region. These local differences in AFB 1 clearance may be due to the pericentral expression of cytochrome P450 enzymes that activate AFB 1 to protein- and DNA-binding metabolites. In conclusion, the present study shows that large spatio-temporal concentration differences exist within the same tissues and its analysis may provide valuable additional information to conventional toxicokinetic studies.
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Classified as Group 1 carcinogens aflatoxins (AFs) are of major concern for food safety and public health. Within the AFs group, aflatoxin B1 (AFB1) occurs at the highest levels in different food products and is considered as the most potent representative. A total of 463 samples of products susceptible to contamination with AFB1 and commonly consumed in Serbia were collected and analyzed. Consumption surveys were performed using a food frequency questionnaire (FFQ) and 24-h recall-based method. Monte Carlo simulation of 100,000 iterations was performed to estimate the intake of AFB1 through each food category, while a simple distribution approach was performed to estimate overall exposure of tested population groups. Risk characterization was performed by calculation of the Margin of Exposure (MOE) and by calculation of the number of possible hepatocellular carcinoma (HCC) cases. The highest exposure was observed in children with the mean overall estimated daily intake (EDI) in the range of 0.79-1.10 and 1.20-1.66 ng kg⁻¹ bw day⁻¹, followed by adolescents 0.56-0.81 and 0.94-1.32 ng kg⁻¹ bw day⁻¹, adult females 0.52-0.72 and 0.56-0.76 ng kg⁻¹ bw day⁻¹ and adult males with the mean overall EDI in the range of 0.39-0.56 and 0.47-0.66 ng kg⁻¹ bw day⁻¹ depending on consumption survey method and for the lower (LB) and upper bound (UB) scenario. MOE values that resulted from the mean values of the overall EDI of AFB1 were low, indicating high concern for all population groups. Based on obtained mean values of the overall EDI higher estimates of possible HCC cases caused by exposure to AFB1 were in the range of 0.01-0.02 cases/year/10⁵ individuals, depending on the population group.
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Analytical methods were validated for the evaluation of acetaldehyde and formaldehyde, which are harmful chemicals, using solid-phase microextraction-gas chromatography/mass spectrometry in four different matrices. Typical home-cooking methods including boiling, pan-frying, and stir-frying, were applied to beef, rapeseed oil, canned pork ham, egg, and rice wine. In addition, monosaccharides, disaccharides, alanine, and glycine were heated for the formation of both aldehydes. All validation parameters, including accuracy, precision, limit of detection, limit of quantification, and uncertainty, for four different matrices were within recommended ranges, confirming the validity of the current method. Acetaldehyde contents ranged from undetectable to 17.92 μg/g and formaldehyde contents ranged from undetectable to 0.27 μg/g. Generally, boiling decreased both aldehydes except acetaldehyde in egg. Pan- and stir-frying increased both aldehyde content substantially in rapeseed oil whereas pan-frying increased acetaldehyde content in canned pork ham and egg. Fructose and sucrose produced higher content of both aldehydes than maltose and glucose when heated. Depending on food type, the cooking process had slightly different effects on the contents of acetaldehyde and formaldehyde.
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Background. The improper recycling of electronic waste (e-waste) by informal recyclers often leads to contamination of the environment. E-waste contains organic and inorganic compounds along with heavy metals and trace elements. These pollutants can have a negative effect on humans. Biomonitoring can provide information on the sources, amount,geographical distribution, and adverse health effects of contaminants. Objectives. The present study aimed to assess risks to the health of informal e-waste recyclersin Payatas, the Philippines due to their exposure to e-waste toxicity by examining thepresence of micronuclei in buccal epithelium cells. Methodology. Frequencies of binucleated cells (BNc) and abnormal cells were obtained from the buccal epithelium of the study population composed of e-waste exposed recyclers (n=40) and a control group (n=52). Descriptive statistics and regression analysis were employed forthe data analysis. Results. Participants’ gender, occupation, smoking status, alcohol consumption, and the number of karyolitic cells of both groups were significantly associated. Only occupation in e-waste recycling and length of e-waste exposure were significantly associated in terms of the number of abnormal cells and micronuclei. Similar trends were found in the linear regressionanalysis drawn from participants’ length of e-waste exposure with a significance of R2= 7346, indicating that as the length of e-waste exposure increased, the number of micronuclei found in the participants' buccal epithelium cells increased as well. Conclusions. Longer exposure to e-waste materials may induce genotoxic damage in human cells which is a serious concern, leading to adverse effects to human health. Competing Interests. The authors declare no competing financial interests
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The ends of chromosomes shorten at each round of cell division, and this process is thought to be affected by occupational exposures. Occupational hazards may alter telomere length homeostasis resulting in DNA damage, chromosome aberration, mutations, epigenetic alterations and inflammation. Therefore, for the protection of genetic material, nature has provided a unique nucleoprotein structure known as a telomere. Telomeres provide protection by averting an inappropriate activation of the DNA damage response (DDR) at chromosomal ends and preventing recognition of single and double strand DNA (ssDNA and dsDNA) breaks or chromosomal end-to-end fusion. Telomeres and their interacting six shelterin complex proteins in coordination act as inhibitors of DNA damage machinery by blocking DDR activation at chromosomes, thereby preventing the occurrence of genome instability, perturbed cell cycle, cellular senescence and apoptosis. However, inappropriate DNA repair may result in the inadequate distribution of genetic material during cell division, resulting in the eventual development of tumorigenesis and other pathologies. This article reviews the current literature on the association of changes in telomere length and its interacting proteins with different occupational exposures and the potential application of telomere length or changes in the regulatory proteins as potential biomarkers for exposure and health response, including recent findings and future perspectives.
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Mycotoxins are naturally occurring fungal metabolites that are associated with health hazards and are widespread in cereals including maize. The most common mycotoxins in maize that occur at relatively high levels are fumonisins (FBs), zearalenone, and aflatoxins; furthermore, other mycotoxins such as deoxynivalenol and ochratoxin A are frequently present in maize. For these toxins, maximum levels are laid down in the European Union (EU) for maize raw materials and maize‐based foods. The current review article gives a comprehensive overview on the different mycotoxins (including mycotoxins not regulated by EU law) and their fate during secondary processing of maize, based on the data published in the scientific literature. Furthermore, potential compliance with the EU maximum levels is discussed where appropriate. In general, secondary processing can impact mycotoxins in various ways. Besides changes in mycotoxin levels due to fractionation, dilution, and/or concentration, mycotoxins can be affected in their chemical structure (causing degradation or modification) or be released from or bound to matrix components. In the current review, a special focus is set on the effect on mycotoxins caused by different heat treatments, namely, baking, roasting, frying, (pressure) cooking, and extrusion cooking. Production processes involving multiple heat treatments are exemplified with the cornflakes production. For that, potential compliance with FB maximum levels was assessed. Moreover, effects of fermentation of maize matrices and production of maize germ oil are covered by this review.
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Benzene is a human carcinogen that requires metabolic activation. We previously observed that benzene and its hydroxylated metabolites induce micronuclei in mammalian cells expressing human CYP2E1. This study was initially aimed to study another endpoint, the induction of gene mutations by those compounds in the same cell models. A V79‐derived cell line expressing human CYP2E1 and sulfotransferase (SULT) 1A1 (V79‐hCYP2E1‐hSULT1A1) pretreated with ethanol (a CYP2E1 stabilizer) was used in the Hprt gene mutagenicity assay. Phenol, hydroquinone, catechol and 1,2,4‐trihydroxybenzene all induced gene mutations, while they were inactive, or only weakly positive (hydroquinone), in parental V79‐Mz cells. Unexpectedly, benzene was non‐mutagenic in both cell lines, but it became positive in V79‐hCYP2E1‐hSULT1A1 cells using regimes of short exposure/long recovery without ethanol pretreatment, for both gene mutations and micronuclei formation. In silico molecular simulation showed binding energies and positions favorable for each compound to be oxidized by human CYP2E1 , benzene demonstrating the highest affinity. By tunnel analysis ethanol binding did not limit benzene to pass tunnel S, which was specifically active for benzene. However, its end product, acetic acid, decreased the occurrence of tunnel S from 5.4 to 2.2%, and extended the length of its bottleneck from 5.5 to 9.0 Å. With residual ethanol molecules still being present in CYP2E1 for a period of time after benzene exposure, the acetic acid formed could limit the entrance of benzene, thus inhibit its metabolic activation. In summary, ethanol may interfere with the activation of benzene to mutagenic metabolites, at least in cultured cells.
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Abstract EFSA was asked to deliver a scientific opinion on the risks to public health related to the presence of aflatoxins in food. The risk assessment was confined to aflatoxin B1 (AFB1), AFB2, AFG1, AFG2 and AFM1. More than 200,000 analytical results on the occurrence of aflatoxins were used in the evaluation. Grains and grain‐based products made the largest contribution to the mean chronic dietary exposure to AFB1 in all age classes, while ‘liquid milk’ and ‘fermented milk products’ were the main contributors to the AFM1 mean exposure. Aflatoxins are genotoxic and AFB1 can cause hepatocellular carcinomas (HCCs) in humans. The CONTAM Panel selected a benchmark dose lower confidence limit (BMDL) for a benchmark response of 10% of 0.4 μg/kg body weight (bw) per day for the incidence of HCC in male rats following AFB1 exposure to be used in a margin of exposure (MOE) approach. The calculation of a BMDL from the human data was not appropriate; instead, the cancer potencies estimated by the Joint FAO/WHO Expert Committee on Food Additives in 2016 were used. For AFM1, a potency factor of 0.1 relative to AFB1 was used. For AFG1, AFB2 and AFG2, the in vivo data are not sufficient to derive potency factors and equal potency to AFB1 was assumed as in previous assessments. MOE values for AFB1 exposure ranged from 5,000 to 29 and for AFM1 from 100,000 to 508. The calculated MOEs are below 10,000 for AFB1 and also for AFM1 where some surveys, particularly for the younger age groups, have an MOE below 10,000. This raises a health concern. The estimated cancer risks in humans following exposure to AFB1 and AFM1 are in‐line with the conclusion drawn from the MOEs. The conclusions also apply to the combined exposure to all five aflatoxins.
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Beer is one the most consumed alcoholic beverage in the world and its contamination with mycotoxins is of public health concern. This study reports a fast and automated analytical procedure based on a multi-heart-cutting two-dimensional liquid chromatography tandem mass spectrometry method using electrospray ionization for the determination of seven mycotoxins (aflatoxins B1, B2, G2 and G1, ochratoxin A, fumonisins B1 and B2) in beers. The developed method was based on the heart-cutting 2D- HPLC technique in which only the specific portions of the first dimension, in the retention time of analytes, were transferred into the second dimension for the further separation and successive determination. The method uses two different chromatographic columns; in the first dimension, 50 μL of sample was injected on first column, and mycotoxins elution regions were collected in a loop and transferred into the second column for the separation of analytes. Each column operated in gradient elution mode in order to eliminate interfering compounds and improve separation and peak shape. After the optimization, the method has been validated according to EU regulation and finally applied for the analysis of forty beer samples collected from Italian supermarkets. Among all mycotoxins studied, fumonisins B1 was the most widely distributed in analysed beers (>21%) in the range from 0.6 to 12.3 ng mL⁻¹. The automated methodology developed was able to determine accurately and simultaneously seven mycotoxins in beer. This provided a significant reduction of sample handle and, consequently of analysis time.
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Head and neck cancers (HNCs) are most often diagnosed at advanced stages, when treatment is both less effective and highly damaging. There is sufficient evidence that formaldehyde and occupations with risk to X-radiation, gamma-radiation exposure are associated with HNCs. There is also some evidence that known carcinogens can also play a role in HNC risk within occupations, including asbestos, strong acid mists, polycyclic aromatic hydrocarbons, textile dust, working in the rubber industry, metal working fluids, and man-made vitreous fibers. Additional studies are necessary to confirm the association of many suspicious agents, occupations, and industries with oral cavity, pharyngeal, and nasopharyngeal cancers. Nevertheless, the knowledge accumulated so far informs prevention and safety at work. Efforts to reduce the burden of head and neck cancers must involve exposure reduction in high-risk occupations.
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Characterization of the chemistry, structure, formation, and metabolism of DNA adducts has been one of the most significant contributions to the field of chemical toxicology. This work provides the foundation to develop analytical methods to measure DNA adducts, define their relationship to disease, and establish clinical tests. Monitoring exposure to environmental and endogenous toxicants can predict, diagnose, and track disease, as well as guide therapeutic treatment. DNA adducts are one of the most promising biomarkers of toxicant exposure owing to their stability, appearance in numerous biological matrices, and characteristic analytical properties. In addition, DNA adducts can induce mutations to drive disease onset and progression and can serve as surrogate markers of chemical exposure. In this perspective article, we highlight significant advances made within the last decade regarding DNA adduct quantitation using mass spectrometry. We hope to expose a broader audience to this field and encourage analytical chemistry labs to explore how specific adducts may be related to various pathologies. One of the limiting factors in developing clinical tests to measure DNA adducts is cohort size – ideally the cohort would allow for model development and then testing of the model to the remaining cohort. The goals of this perspective article are 1) to provide a summary of analyte levels measured using state-of-the-art analytical methods, 2) to foster collaboration, and 3) to highlight areas in need of further investigation.
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Food contamination by aflatoxin B1 (AFB1), produced by mycotoxigenic strains of Aspergillus spp., causes severe medical and economic implications. Essential oils (EOs) are mixtures of eco-friendly natural volatile substances. Their ability to inhibit fungal growth has been investigated, while no data are available about their efficacy in inhibition of AFB1 biosynthesis. This study investigates the efficacy of five different citrus EOs to inhibit the growth and AFB1 synthesis of A. flavus through in vitro tests for a future application in food matrices. AFB1 detection was carried out by LC-ESI-TQD analytical approach. Lemon (Citrus limon (L.) Burm. f.), bergamot (Citrus bergamia Risso), and bitter orange (Citrus aurantium L.) EOs were the most effective causing a 97.88%, 97.04%, and 96.43% reduction in mycelial growth, respectively. Sweet orange and mandarin EOs showed the lowest percentage of mycelial growth reduction. Citrus EOs showed different capacity of AFB1 inhibition (lemon > bitter orange > bergamot > sweet orange > mandarin). Our results showed a dose-dependent antifungal activity of lemon, bitter orange, and bergamot EOs which at 2% (v/v) inhibited both mycelium growth and AFB1 genesis of A. flavus. Our results show that EOs’ use can be a pivotal key to recovery and reuse of citrus fruit wastes and to be used as eco-friendly fungicides for improvement of food safety. The use of EOs obtained at low cost from the residues of citric industry presents an interesting option for improving the profitability of the agriculture.
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The fact that hairdressers are exposed to toxic substances through the handling of creams and smoothing products prompted this study whose aim was to quantify the occupational exposure of hairdressers to formaldehyde by comparing the results of exposure for different types of beauty salon. The study population consisted of 23 beauty salons located in the city of Bauru, São Paulo state, Brazil. The samples were collected by inhaled air tests during the most critical 15-min period of the hair straightening procedure and during the 8-h work shift. The concentrations of formaldehyde contained in the formulations of these products were also evaluated and compared with exposure levels. The results were evaluated according to the exposure limits prescribed in Brazilian (NR15) and North American (US OSHA and US NIOSH) standards. The analysis of the smoothing products showed concentrations of formaldehyde of between 3 and 11% in their compositions, i.e., up to 54 times above the 0.2% limit allowed by the National Agency of Sanitary Surveillance (ANVISA). The present study showed that hairdressers are chronically exposed to high concentrations of formaldehyde in the workplace and these exposures are mainly associated with the work process, where many variables of this process influence the intensity of exposure.
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Aflatoxin (AF) B1, a widespread food and feed contaminant, is bioactivated by drug metabolizing enzymes (DME) to cytotoxic and carcinogenic metabolites like AFB1-epoxide and AFM1, a dairy milk contaminant. A number of natural antioxidants have been reported to afford a certain degree of protection against AFB1 (cyto)toxicity. As the mammary gland potentially participates in the generation of AFB1 metabolites, we evaluated the role of selected natural antioxidants (i.e. curcumin, quercetin and resveratrol) in the modulation of AFB1 toxicity and metabolism using a bovine mammary epithelial cell line (BME-UV1). Quercetin and, to a lesser extent, resveratrol and curcumin from Curcuma longa (all at 5 μM) significantly counteracted the AFB1-mediated impairment of cell viability (concentration range: 96–750 nM). Moreover, quercetin was able to significantly reduce the synthesis of AFM1. The quantitative PCR analysis on genes encoding for DME (phase I and II) and antioxidant enzymes showed that AFB1 caused an overall downregulation of the detoxifying systems, and mainly of GSTA1, which mediates the GSH conjugation of the AFB1-epoxide. The negative modulation of GSTA1 was efficiently reversed in the presence of quercetin, which significantly increased GSH levels as well. It is suggested that quercetin exerts its beneficial effects by depressing the bio-transformation of AFB1 and counterbalancing its pro-oxidant effects.
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The occurrence of aflatoxin M1 (AFM1) in milk samples commercialized in the Metropolitan area of Monterrey (Mexico) was evaluated by employing the competitive enzyme linked immunosorbent assay (ELISA) technique. For this, 84‐fluid milk samples, with diverse origin (80% national production, 20% imported milk) and heat treatments (26% pasteurized and 74% Ultra High Temperature (UHT)‐treated) were collected in different sales points. In all the evaluated samples, the AFM1 was detected, with values oscillating from 0.1 to 1.27 μg/L. According to the Food and Drug Administration (FDA) and Mexican standards, concerning a maximum limit of 0.5 μg/L, 39% of the analyzed samples were out of the standard limit, with different results depending on the milk origin (46% and 18% for national and imported milks, respectively) and heat treatment applied (45% and 23% for UHT and pasteurized samples, respectively). Based on these results, it is necessary a higher effort to control AFM1 levels in milk consumed in Mexico. Practical applications The practical application of this document is to serve as a first approach to know the presence of aflatoxins in milk in northern Mexico, both in domestic and imported products, and under different heat treatments applied and from this, take different measures by authorities and producers with a view to reducing their presence in milk and other dairy products.
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It is well known that a number of substances used in the textile industry can mean not only environmental, but also health problems. The scientific literature regarding potential adverse health effects of chemical substances in that industry is mainly related with human exposure during textile production. However, information about exposure of consumers is much more limited. Although most research on the health effects of chemicals in textiles concern allergic skin reactions, contact allergy is not the only potential human health problem. In this paper, we have reviewed the current scientific information regarding human exposure to chemicals through skin-contact clothes. The review has been focused mainly on those chemicals whose probabilities of being detected in clothes were rather higher. Thus, we have revised the presence of flame retardants, trace elements, aromatic amines, quinoline, bisphenols, benzothiazoles/benzotriazoles, phthalates, formaldehyde, and also metal nanoparticles. Human dermal exposure to potentially toxic chemicals through skin-contact textiles/clothes shows a non-negligible presence in some textiles, which might lead to potential systemic risks. Under specific circumstances of exposure, the presence of some chemicals might mean non-assumable cancer risks for the consumers.
Chapter
Olefins are important industrial chemicals. Small-molecule olefins are potentially toxic and mutagenic/carcinogenic due to their bioactivation by cytochrome P450s to yield epoxides. In this chapter, we focus on an alternative bioactivation pathway, i.e., myeloperoxidase (MPO)-mediated metabolism of olefins at physiological conditions, which results in the formation of chlorohydrins as major products. Conversion of representative olefins, 1,3-butadiene (BD), styrene, and cyclohexene, to corresponding chlorohydrins via this pathway has been demonstrated. Because MPO is almost exclusively present in the hematopoietic system and blood, the MPO pathway may be active in these systems and contribute to hematopoietic toxicity of olefins. In this regard, several chlorohydrins are known to be converted nonenzymatically or enzymatically to yield reactive epoxides, aldehydes, and/or ketones, and many of these chlorohydrins and their secondary products exhibit toxicity and mutagenicity/carcinogenicity. The evidence suggesting that the MPO pathway plays a significant role in BD metabolism, toxicity, and mutagenicity/carcinogenicity is discussed.
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The present study evaluated an occupational exposure level for formaldehyde employing benchmark dose (BMD) approach. Dose–response relationship was determined by utilizing cumulative occupational exposure dose and DNA damage. Based on this goal, outcome of comet assay for some Iranian exposed people in occupational exposure individuals was used. In order to assess formaldehyde exposure, 53 occupationally exposed individuals selected from four melamine tableware workshops and 34 unexposed subjects as a control group were examined. The occupational exposure dose was carried out according to the NIOSH-3500 method, and the DNA damage was obtained by employing comet assay in peripheral blood cells. EPA Benchmark Dose Software was employed for calculating BMD and BMDL. Cumulative exposure dose of formaldehyde was between of 2.4 and 1972 mg. According to the findings of the current study, the induction of DNA damage in the exposed persons was increased tail length and tail moment (p < 0.001), when compared to controls. Finally, an acceptable dose–response relationship was obtained in three-category information between formaldehyde cumulative exposure doses and genetic toxicity. BMDL was 0.034 mg/m³ (0.028 ppm), corresponding to genetic damage of peripheral blood cells. It can be concluded that the occupational permissible limit in Iranian people could be at levels lower than OSHA standards.
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bstract | Aflatoxin B1 (AFB1), is a mycotoxin found in food and feed, exerts harmful effects on humans and animals. The liver is the earliest target organ of AFB1, and its effects have been evaluated in animal models exposed to acute or chronic doses. For this reason, this study was planned to detoxify the AFB1 by ginger root extracts in mice. Forty mice were caged to four experimental groups and treated for 5 weeks with extracts and with or without AFB1. Blood samples were collected and removal the livers at the end of an experimental period for serum biochemical analysis of Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), and Gamma-glutamyl transpeptidase (GGT) and study the histopathological changes of the liver. The results indicated that mice treated with AFB1 alone showed a significant increase (P≤0.05) in all parameters tested (79.01± 1.05 IU/L), (199± 1.15 IU/L), and (27.19±0.97 IU/L) respectively, whereas no significant differences were noticed in group treated extract alone while in group treated ginger root extract with AFB1 could significantly lower the serum activity level of all parameters tested to reach (38.10± 1.01 IU/L), (94.96± 1.22 IU/L), and (15.08±1.21 IU/L) respectively. The histopathological changes of liver showed congestion of central vein, apoptotic cells and formation of a mitotic figure in a group treated AFB1 alone, whereas group treated AFB1 with extract showed regeneration in most hepatocytes normal structure. These results clearly indicated that AFB1 has stressful effects on the hepatic tissues and ginger root extract was found most effective in the prevention of Aflatoxin-induced toxicity in mice. (PDF) Detoxification of Aflatoxin B1 by Ginger Extract in Mice. Available from: https://www.researchgate.net/publication/327440979_Detoxification_of_Aflatoxin_B1_by_Ginger_Extract_in_Mice [accessed Jan 19 2019].
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The effect of gamma irradiation under various packaging atmospheres on chemical constituents and antibacterial properties of turmeric rhizome volatile oil has been studied. The turmeric rhizome powder was packaged under different atmospheres (air, N₂, and vacuum) by high‐barrier multilayered film (Pet/EVOH–PA/LDPE) and they were gamma irradiated at dose of 5, 10, and 15 kGy. According to the results, gamma irradiation under different atmospheres of packaging did not change antibacterial properties of the volatile oil. However, oxygenated sesquiterpenes which are the major chemical constituent of the volatile oil increased by irradiation significantly by 6.45% (at 15 kGy under air packaging) (p < .05). Also, modified atmosphere packaging (MAP) was more effective to improve these active compounds, significantly (p < .05). Since gamma irradiation may cause chemical oxidation, isomerization, and hydroxylation of volatile oil's constituents, it concluded that these changes could be minimized under MAP in turmeric rhizome volatile oil, significantly. Practical applications Ionizing radiation as a cold‐pasteurization method has widespread and growing applications in decontamination of spice and condiments but, there are lack of information or contradictory results on the effects of irradiation on chemical constituents and physicochemical properties of them. Our results showed that gamma irradiation caused quantitative not qualitative changes on chemical constituents of turmeric's volatile oil. Irradiation did not have effect on antibacterial properties of turmeric volatile oils in all doses under different packaging atmospheres. The outcome of this research demonstrated irradiation resulted in improving oxygenated sesquiterpenes contents which are the major components of turmeric volatile oil. It should be noted that irradiation under modified atmosphere (N2 and vacuum) was more effective in improving these constituents, too. Statistically, the effect of N2 and vacuum was the same but practically vacuum packaging is recommended.
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