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Worldwide pesticide usage and its impacts on ecosystem

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Pesticides are extensively used in modern agriculture and are an effective and economical way to enhance the yield quality and quantity, thus ensuring food security for the ever-growing population around the globe. Approximately, 2 million tonnes of pesticides are utilized annually worldwide, where China is the major contributing country, followed by the USA and Argentina, which is increasing rapidly. However, by the year 2020, the global pesticide usage has been estimated to increase up to 3.5 million tonnes. lthough pesticides are beneficial for crop production point of view, extensive use of esticides can possess serious consequences because of their bio-magnification and persistent nature. Diverse pesticides directly or indirectly polluted air, water, soil and verall ecosystem which cause serious health hazard for living being. In the present manuscript, an attempt has been made to critically review the global usage of different pesticides and their major adverse impacts on ecosystem, which will provide guidance for a wide range of researchers in this area.
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SN Applied Sciences (2019) 1:1446 |
Review Paper
Worldwide pesticide usage andits impacts onecosystem
AnketSharma1,2 · VinodKumar3· BabarShahzad4· MohsinTanveer4· GaganPreetSinghSidhu5· NehaHanda2,6·
SukhmeenKaurKohli2· PoonamYadav2· AditiShreeyaBali7· RipuDamanParihar8· OwiasIqbalDar9·
KirpalSingh9· ShivamJasrotia9· PalakBakshi2· M.Ramakrishnan10· SandeepKumar11· RenuBhardwaj2·
© Springer Nature Switzerland AG 2019
Pesticides are extensively used in modern agriculture and are an eective and economical way to enhance the yield qual-
ity and quantity, thus ensuring food security for the ever-growing population around the globe. Approximately, 2 million
tonnes of pesticides are utilized annually worldwide, where China is the major contributing country, followed by the USA
and Argentina, whichis increasing rapidly. However, by the year 2020, the global pesticide usage has been estimated
to increase up to 3.5 million tonnes. Although pesticides are benecial for crop production point of view, extensive use
of pesticides can possess serious consequences because of their bio-magnication and persistent nature. Diverse pes-
ticides directly or indirectly polluted air, water, soil and overall ecosystem which cause serious health hazard for living
being. In the present manuscript, an attempt has been made to critically review the global usage of dierent pesticides
and their major adverse impacts on ecosystem, which will provide guidance for a wide range of researchers in this area.
Keywords Global pesticide usage· Pesticide application· Pesticide bio-magnication· Pesticide ecotoxicology
1 Introduction
Pesticides are the chemicals (natural or synthetic)
employed in various agricultural practices to control pests,
weeds and diseases in plants. Pesticides include a wide
range of herbicides, insecticides, fungicides, rodenticides,
nematicides, etc. In the process of agricultural develop-
ment, pesticides became a vital tool for plant protection
and for enhancing crop yield. Approximately, 45% of the
annual food production is lost due to pest infestation;
therefore, eective pest management by using wide range
of pesticides is required to confront pests and to increase
the crop production [1]. However, in the last half of the
nineteenth century, robust growth in the world economy
including both industrial and agricultural sectors has led
to the progressive mount in the generation and utiliza-
tion of agriculture-based chemicals which often induce
calamitous eects on the environment. Injudicious use of
pesticides and other persistent organic pollutants in agri-
cultural soils have devastated future repercussions. The
Received: 31 May 2019 / Accepted: 11 October 2019 / Published online: 21 October 2019
Anket Sharma, Vinod Kumar and Babar Shahzad have contributed equally to this work.
* Anket Sharma, | 1State Key Laboratory ofSubtropical Silviculture, Zhejiang A&F University, Hangzhou311300,
China. 2Plant Stress Physiology Lab, Department ofBotanical andEnvironmental Sciences, Guru Nanak Dev University, Amritsar,
Punjab143005, India. 3Department ofBotany, DAV University, Sarmastpur,Jalandhar, Punjab144012, India. 4School ofLand andFood,
University ofTasmania, Hobart, TAS, Australia. 5Department ofApplied Sciences, UIET, Chandigarh160014, India. 6Department
ofBotany, School ofBioengineering andBiosciences, Lovely Professional University, Phagwara, Punjab144411, India. 7Department
ofBotany, M.C.M. DAV College forWomen, Chandigarh160036, India. 8Department ofZoology, DAV University, Sarmastpur,Jalandhar,
Punjab144012, India. 9Department ofZoology, Guru Nanak Dev University, Amritsar143005, India. 10Division ofPlant Biotechnology,
Entomology Research Institute, Loyola College, Chennai, India. 11Department ofEnvironmental Sciences, DAV University,
Sarmastpur,Jalandhar, Punjab144012, India.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Pesticides are chemicals used to reduce, remove, prevent, or destroy any pest.Insecticides, fungicides, herbicides, molluscicides, nematicides, bactericides, piscicides, rodenticides, avicides, animal repellents, antimicrobials, and soil fumigants are examples of pesticides. 1 Pest infestation destroys approximately 45% of annual food production. 2 Pesticide use helps to keep pests away from crops and can improve crop yield and quality. 1 In modern times, there are more than 500 substances that are authorized and utilized globally as pesticides or their derivatives. Following the conclusion of the Second World War, the application of pesticides in the farming sector has experienced a steady escalation, resulting in heightened food production worldwide. ...
... Organophosphates, organochlorins, and neonicotiniods are some of the most commonly employed pesticides in India. 3 However, due to their unscientific and excessive application, 80 to 90% of pesticides applied reach organisms other than their target organism and are deposited on non-target soil and water, contributing to agro-ecosystem pollution 3,2 Pesticides possess the capability to disturb the functioning and composition of the ecosystem as they enter the food chain and have adverse effects on the biotic elements of the ecosystem, including soil organisms, plants, animals in the wild, aquatic creatures, and domesticated animals.The widespread presence and enduring impact of diverse pesticides and organic pollutants derived from agriculture have caused significant harm to humanity due to their ability to accumulate in living organisms and their high levels of toxicity. These pesticides have been observed to disrupt the proper functioning of the endocrine and reproductive systems in various organisms. ...
... Specific pesticides such as dichlorodiphenyltrichloroethane (DDT), chlordane, aldrin, dieldrin, endrin, mirex, heptachlor, and hexachlorobenzene have detrimental effects on both human health and the environment. 2 According to the Indian Council of Medical Research (ICMR), approximately 1 million lives are lost annually worldwide due to the persistent effects of pesticide poisoning, resulting in long-term illnesses. 3 Numerous techniques for remedying the presence of pesticides in soil have been devised and put into practice, with the aim of eradicating, lessening, and segregating them.However, remediation through the separation and destruction of soil contaminants is time-consuming and costly. ...
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The use of pesticides presents a looming danger to the living elements of our ecological system, crops, and the well-being of our species. As an outcome, various organic contaminants pollute the soil. Different physical, chemical, and biological remediation techniques have been employed for the decontamination of pesticide-polluted soils. Remediation technology should always be affordable, on-site or in-situ, and capable of restoring the soil's natural functionality. The presence of multiple pesticides can pose challenges in effectively remediating them from the soil. The present work examines the scientific literature on the benefits and drawbacks of various existing and emerging soil remediation techniques. Customized technology choices and designs for specific site conditions enhance the effective cleanup of polluted areas. The present study, which evaluates and contrasts various technological approaches, shall serve as an invaluable tool for determining the optimal soil remediation method for a given contamination dilemma.
... On a global scale, approximately 2 million tons of pesticides are used annually (Sharma et al., 2019). This production scenario generates several implications, such as the use of pesticides in the crops with potential impacts on terrestrial and aquatic ecosystems in the edge-of-fields. ...
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The intensive use of pesticides causes harmful effects on ecosystems, and remediation techniques can reduce the ecotoxicity of contaminated soils. Sugarcane straw is a feasible feedstock for biochar production, and it is abundant in the ethanol industry. In this sense, this study assessed the application of biochar from sugarcane straw to reduce the ecotoxicity of soils contaminated with the pesticides fipronil and 2,4-D, alone and in a mixture. Tests at the microcosm level (28 days) evaluated the influence of biochar on the terrestrial worm Enchytraeus crypticus and the eudicot plant Eruca sativa L. At the end of the experiment, elutriate solutions were prepared with soil samples to assess responses on E. sativa and on the cladoceran Daphnia similis. Fipronil and 2,4-D decreased the reproduction of E. crypticus in microcosms, particularly on treatments with fipronil. Biochar reduced the ecotoxicity of fipronil in soils, increasing the reproduction of E. crypticus by 43% compared with soils without biochar. However, the control with biochar showed a reproduction reduction of 23% when compared with the control without biochar. In soils with 2,4-D, the germination rates and shoot growth of E. sativa were 2 times greater in biochar-remediated soils compared with untreated soils. Considering the exposure to elutriate, the application of biochar in soils with 2,4-D improved the growth (by 45%) and germination (by 34%) of E. sativa. No effects were identified on D. similis at any exposure scenario. Therefore, sugarcane straw biochar can be a viable alternative for reducing the ecotoxicity of pesticides in soils.
... Ich zadaniem jest ochrona roślin uprawnych przed agrofagami, które przyczyniają się do utratay plonów i pogorszenia ich jakości [1]. Światowe zużycie pestycydów w latach 2000-2019 wzrosło o 36% osiągając wartość 4,2 mln ton [2], z czego około 47,5% stanowią herbicydy, 29,5% insektycydy, 17,5% fungicydy, 5,5% -inne [3]. Pomimo pozytywnych aspektów związanych z zastosowaniem tych preparatów, ich wykorzystanie niesie za sobą szereg zagrożeń. ...
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Abstract The purpose of the study was to assess the susceptibility of phytopathogenic fungi to essential oils from hop cones. The material for the study consisted of filamentous fungi of the genus Fusarium – F. oxysporum and F. culmorum isolated from infested wheat grains. Using the hydrodistillation method in the Deryng apparatus, essential oils were obtained from hop cones of the Marynka and Iunga varieties. The antifungal activity of the extracted preparations was evaluated by poisoned food technique in PDA medium. The absolute control sample was commercial thyme oil from ETJA company. The samples were incubated at 25 ±3°C for 14 days. Mycelial growth rate indices were determined from the obtained results. Phytopathogen susceptibility tests on the preparations obtained showed varying results in growth inhibition, both due to the Fusarium species used and the hop variety from which the extract was obtained. The F. oxysporum strain was characterized by higher sensitivity to the applied essential oils, but the lowest concentration of oil from hop cones of the Marynka variety resulted in growth stimulation of F. oxysporum. Lower mycelial growth rate index results were observed for the oil obtained from hop cones of the Iunga variety. Commercial thyme oil caused complete inhibition of mycelial growth at the lowest applied concentration. In response to the applied extracts, the mycelium of F. oxysporum secreted a pinkish-brown dye, while in the case of F. culmorum a reduction in the intensity of the brown dye secreted was observed. Keywords: Humulus lupulus L., Marynka variety, Iunga variety, fungistatic activity, antifungal activity Streszczenie Celem badań była ocena wrażliwości fitopatogennych grzybów na olejki eteryczne z szyszek chmielu. Materiał do badań stanowiły grzyby strzępkowe z rodzaju Fusarium – F. oxysporum i F. culmorum wyizolowane z porażonych ziarniaków pszenicy. Metodą hydrodestylacji w aparacie Derynga otrzymano olejki eteryczne z szyszek chmielu odmian Marynka i Iunga. Aktywność przeciwgrzybiczą pozyskanych preparatów oceniono metodą zatruwania podłóż w pożywce PDA. Bezwzględną próbę kontrolną stanowił handlowy olejek tymiankowy firmy ETJA. Próby inkubowano w temperaturze 25 ±3°C przez 14 dób. Na podstawie uzyskanych wyników przyrostu grzybni wyznaczono indeksy tempa wzrostu. Badania wrażliwości fitopatogenów na uzyskane preparaty wykazały zróżnicowane wyniki zahamowania wzrostu, zarówno ze względu na wykorzystany gatunek Fusarium, jak i odmianę chmielu, z której uzyskano ekstrakt. Wyższą wrażliwością na zastosowane olejki cechował się szczep F. oxysporum, jednak najniższe zastosowane stężenie olejku z szyszek chmielu odmiany Marynka spowodowało stymulacje wzrostu tego szczepu. Niższe wyniki indeksu tempa wzrostu grzybni otrzymano dla olejku uzyskanego z szyszek chmielu odmiany Iunga. Handlowy olejek tymiankowy powodował całkowite zahamowanie wzrostu grzybni już w najniższym zastosowanym stężeniu. W odpowiedzi na zastosowane ekstrakty grzybnia F. oxysporum wydzielała różowo-brązowy barwnik, natomiast w przypadku F. culmorum zaobserwowano zmniejszenie intensywności wydzielanego brązowego barwnika. Słowa kluczowe: Humulus lupulus L., odmiana Marynka, odmiana Iunga, aktywność fungistatyczna, aktywność przeciwgrzybicza
... The inclusion of these public goods would increase the total economic value of LF-NPC 52 . Additionally, our study does not undertake a comprehensive appraisal of the positive rami cations arising from a reduced use of synthetic pesticides, such as cost savings in water puri cation, health bene ts for workers or nearby residents 53,54 . Furthermore, although we explore the potential positive feedback loop of an enhanced landscape design supporting LF-NPC, we did only account for the costs related to reduced pesticides use and did not explore the costs associated with redesigning the agricultural landscape to increase LF-NPC potential. ...
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Future trajectories of agricultural productivity need to incorporate environmental targets, including the reduction of pesticides use. Landscape features supporting natural pest control (LF-NPC) offer a nature-based solution that can serve as a partial substitute for synthetic pesticides, thereby supporting future productivity levels. Here, we introduce a novel approach to quantify the contribution of LF-NPC to agricultural yields and its associated economic value to crop production in a broad-scale context. Using the European Union as case study, we combine granular farm-level data, a spatially explicit map of LF-NPC potential across agricultural land, and a regional agro-economic supply and market model. The results reveal that farms located in areas characterized by higher LF-NPC potential experience lower productivity losses in a context of reduced synthetic pesticides use. Specifically, we estimate that a one-unit increase in LF-NPC potential, on average, leads to a 6.1% increase in agricultural income. These results highlight the significance of LF-NPC for agricultural production, and provide a valuable reference point for farmers and policymakers aiming to successfully invest in landscape features to achieve pesticides reduction targets.
... The use of insecticide has been the primary method for preventing and controlling TPB in the mid-south cotton growing area, with a variety of classes employed such as organophosphates, carbamates, neonicotinoids, pyrethroids, insect growth regulators, and sulfoximine [5][6][7][8][9]. Pyrethroids, which account for 30% of the global pesticide market, are synthetic insecticides based on natural pyrethrins found in Chrysanthemum flowers [10]. Over the past few decades, pyrethroids were extensively used to control agricultural crop pests and human disease vectors [11]. ...
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Over the past several decades, the extensive use of pyrethroids has led to the development of resistance in many insect populations, including the economically damaging pest tarnished plant bug (TPB), Lygus lineolaris, on cotton. To manage TPB resistance, several commercially formulated pyrethroid-containing binary mixtures, in combination with neonicotinoids or avermectin are recommended for TPB control and resistance management in the mid-South USA. This study aimed to evaluate the toxicity and resistance risks of four formulated pyrethroid-containing binary mixtures (Endigo, Leverage, Athena, and Hero) on one susceptible and two resistant TPB populations, which were field-collected in July (Field-R1) and October (Field-R2), respectively. Based on LC50 values, both resistant TPB populations displayed variable tolerance to the four binary mixtures, with Hero showing the highest resistance and Athena the lowest. Notably, the Field-R2 exhibited 1.5–3-fold higher resistance compared to the Field-R1 for all four binary insecticides. Moreover, both resistant TPB populations demonstrated significantly higher resistance ratios towards Hero and Leverage compared to their corresponding individual pyrethroid, while Endigo and Athena showed similar or lower resistance. This study also utilized the calculated additive index (AI) and co-toxicity coefficient (CTC) analysis, which revealed that the two individual components in Leverage exhibited antagonist effects against the two resistant TPB populations. In contrast, the two individual components in Endigo, Hero, and Athena displayed synergistic interactions. Considering that Hero is a mixture of two pyrethroids that can enhance the development of TPB resistance, our findings suggest that Endigo and Athena are likely superior products for slowing down resistance development in TPB populations. This study provides valuable insight for selecting the most effective mixtures to achieve better TPB control through synergistic toxicity analysis, while simultaneously reducing economic and environmental risks associated with resistance development in the insect pest.
... Los plaguicidas ingresan a cuerpos de agua a través de la escorrentía, lixiviación o por aplicación directa, los cuales disminuyen el oxígeno disuelto en el agua afectando las especies que habitan en éstos (Mahmood et al., 2016;Sharma et al., 2019). Por otro lado, Woodrow et al. (2018) y Kaur et al. (2019) señalan que alrededor del 90% de los plaguicidas aplicados se pueden volatilizar depositándose en suelos, océanos, lagos, ríos y otros cuerpos de agua, causando afectaciones en los ecosistemas. ...
Pollution of surface waters is a global threat, with particular concern about pesticides due to their severe negative effects on ecosystem functioning and human health. The aims of this study were to identify the spatiotemporal patterns of water and sediment quality, and the key variables related to the variation in pesticide pollution, in headwater streams (surrounding land uses: crop or mixed crop-livestock systems) and floodplain streams (surrounding land uses: urban development or natural wetland) of the Paraná River basin in the central area of Argentina. We found significant differences in water and sediment quality related to local land uses among headwater streams, but not among floodplain streams. These differences were more noticeable during spring than during autumn. Pesticides were widespread in all the streams, independently of the surrounding land use, reflecting the combination of local inputs and the role of floodplain hydrological connectivity in transporting pollutants from upstream sources. The most frequently detected compound was atrazine (75 %), whereas the highest concentration of an individual compound was observed for the glyphosate metabolite aminomethylphosphonic acid (AMPA, up to 4 μg L−1). The significant explanatory variables for pesticide pollution were turbidity, chromophoric dissolved organic matter (CDOM), sub-basin area, side slope of streams (positive relations), wetland cover, and precipitations (negative relations). Our results can be useful for the design of monitoring programs that capture the spatial and temporal variability of pesticide pollution.
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Pesticides are applied all over the world to protect plants from pests. However, their application also causes toxicity to plants, which negatively affects the growth and development of plants. Pesticide toxicity results in reduction of chlorophyll and protein contents, accompanied by decreased photosynthetic efficiency of plants. Pesticide stress also generates reactive oxygen species which causes oxidative stress to plants. To attenuate the negative effects of oxidative stress, the antioxidative defense system of plants gets activated, and it includes enzymatic antioxidants as well as non-enzymatic antioxidants. The present review gives an overview of various physiological responses of plants under pesticide toxicity in tabulated form.
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In present study, the data of pesticide use, crop (the total of cereals, pulses, roots and tubers, oil crops, fibre crops, fruits, vegetables, and melons, etc.) production and the area harvested of the world and major countries for the period between 1990 and 2014 were collected, organized and summarized from FAOSTAT. First I proposed an index to measure the productive efficiency of pesticide use, cost / benefit, which refers to the amount of pesticide use to produce a certain amount of crop in a year. Theoretical relationship between crop yield and cost / benefit of pesticide use is a model with the sigmoid curve: y = a + b / (1 + e^(c-rx)), where y is crop yield, x is cost / benefit of pesticide use. The results showed that global cost / benefit of pesticide use (total) increased with time during 1990 to 2007, and declined since 2007. Pesticide use (total) (kg / ha) had the similar trend. Global insecticides, herbicides, and fungicides & bactericides use and cost / benefit declined with time since 2007. During 2010 and 2014, mean pesticide cost / benefit was 0.645 g pesticide use (total) / kg crop production, and mean annual pesticide use (total) was 2.784 kg /ha. Mean cost / benefit of insecticides, herbicides and fungicides & bactericides use between 2010 and 2014 were 0.051, 0.16 and 0.074 g / kg crop production, respectively, and mean annual use of insecticides, herbicides and fungicides & bactericides were 0.221, 0.69 and 0.32 kg / ha, respectively. Globally, the cost / benefit of dithiocarbamates, bipiridils, carbamates insecticides, and organo-phosphates, and the use of dithiocarbamates, bipiridils, and carbamates insecticides have significantly declined since 2007, and conversely, the cost / benefit of triazoles / diazoles and the use of triazoles / diazoles, plant growth regulators, and amides, have significantly increased since 2007. Of the major countries, the averaged annual cost / benefit of pesticide use (total) of Brazil during 2010 to 2014 was the greatest (1.883), followed by Japan (1.846), Mexico (1.678), China (1.243), Canada (0.979), USA (0.8733), France (0.708), Germany (0.673), UK (0.55), and India (0.089). The averaged annual pesticide use (total) (kg / ha) of Japan during 2010 to 2014 was the greatest (18.94), followed by China (10.45), Mexico (7.87), Brazil (6.166), Germany (5.123), France (4.859), UK (4.034), USA (3.886), and India (0.261). Profile of development, production and use of pesticides in China was discussed in detail. Various trends were analysed and a variety of valuable data were provided.
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To protect crops from pests, pesticides are used. Pesticides also cause toxicity to crop plants and persist in plant parts in the form of pesticide residues. Brassinosteroids (BRs) are known for their protective role in plants under various abiotic stresses like heavy metal, drought, temperature, pesticide etc. BRs ameliorate pesticide toxicity in intact plants by activating the antioxidative defence system. BRs also enhance the degradation of pesticides that leads to reduction in pesticide residues in plant parts. Present review gives an updated information about the protective roles of BRs in plants and the underlying mechanisms under pesticide stress.
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Agrochemicals have enabled to more than duplicate food production during the last century, and the current need to increase food production to feed a rapid growing human population maintains pressure on the intensive use of pesticides and fertilizers. However, worldwide surveys have documented the contamination and impact of agrochemical residues in soils, and terrestrial and aquatic ecosystems including coastal marine systems, and their toxic effects on humans and nonhuman biota. Although persistent organic chemicals have been phased out and replaced by more biodegradable chemicals, contamination by legacy residues and recent residues still impacts on the quality of human food, water, and environment. Current and future increase in food production must go along with production of food with better quality and with less toxic contaminants. Alternative paths to the intensive use of crop protection chemicals are open, such as genetically engineered organisms, organic farming, change of dietary habits, and development of food technologies. Agro industries need to further develop advanced practices to protect public health, which requires more cautious use of agrochemicals through prior testing, careful risk assessment, and licensing, but also through education of farmers and users in general, measures for better protection of ecosystems, and good practices for sustainable development of agriculture, fisheries, and aquaculture. Enhanced scientific research for new developments in food production and food safety, as well as for environmental protection, is a necessary part of this endeavor. Furthermore, worldwide agreement on good agriculture practices, including development of genetically modified organisms (GMOs) and their release for international agriculture, may be urgent to ensure the success of safe food production. © 2017 John Wiley & Sons Ltd and the Association of Applied Biologists.
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Urban stormwater samples were collected from five aquatic systems in Melbourne, Australia, on six occasions between October 2011 and March 2012 and tested for 30 herbicides and 14 trace metals. Nineteen different herbicides were observed in one or more water samples from the five sites; chemicals observed at more than 40% of sites were simazine (100%), MCPA (83%), diuron (63%) and atrazine (53%). Using the toxicity unit (TU) concept to assess potential risk to aquatic ecosystems, none of the detected herbicides were considered to pose an individual, group or collective short-term risk to fish or zooplankton in the waters studied. However, 13 herbicides had TU values suggesting they might have posed an individual risk to primary producers at the time of sampling. Water quality guideline levels were exceeded on many occasions for Cd, Cu, Cr, Pb and Zn. Similarly, RQmed and RQmax exceeded 1 for Cd, Cr, Cu, Mn, Ni, Pb, V and Zn. Almost all the metals screened exceeded a log10TU of −3 for every trophic level, suggesting that there may have been some impact on aquatic organisms in the studied waterbodies. Our data indicate that Melbourne’s urban aquatic environments may be being impacted by approved domestic, industrial and sporting application of herbicides and that stormwater quality needs to be carefully assessed prior to reuse. Further research is required to understand the performance of different urban stormwater wetland designs in removing pesticides and trace metals. Applying the precautionary principle to herbicide regulation is important to ensure there is more research and assessment of the long-term ‘performance’ standard of all herbicides and throughout their ‘life cycle’. Implementing such an approach will also ensure government, regulators, decision makers, researchers, policy makers and industry have the best possible information available to improve the management of chemicals, from manufacture to use.
Heavy metal (HM) and pesticide contamination in the soil is of major concern in the present era. Both of these contaminants disturb soil microflora and adversely affect the growth and development of plants. The soil contamination can be reduced by ecofriendly techniques. The use of endophytic bacteria (EB) in the rhizosphere is one such technique where EB reduce the HM and pesticide contaminants in the soil. They can efficiently reduce the HM and pesticide concentration in the soil by enhancing the phytoremediating efficiency of plants. Moreover, EB can also degrade the pesticides in soil by producing various hormones and enzymes which ultimately result in promotion of the growth of plants. Hence, keeping in mind the efficiency of EB in reducing the HM and pesticide contamination in soil, the present review gives a detailed view of HM and pesticide detoxification by these bacteria.
Persistent organic pollutants were assessed in Humboldt Penguins ( Spheniscus humboldti) from the Punta San Juan Marine Protected Area, Peru, in the austral winter of 2009. Plasma samples from 29 penguins were evaluated for 31 polychlorinated biphenyl (PCB) congeners and 11 organochlorine pesticides (OCPs) by using gas chromatography coupled to an ion trap mass spectrometer and for 15 polybrominated diphenyl ether (PBDE) congeners by using gas chromatography coupled with high-resolution mass spectrometry. The detection rate for PCBs in the samples was 69%, with congeners 105, 118, 180, and 153 most commonly detected. The maximum ΣPCB concentration was 25 ng/g. The detection rate for DDT, DDD, and/or DDE was higher than for other OCP residues (90%; maximum concentration=10 ng/g). The detection rate for PBDEs was 86%, but most concentrations were low (maximum ΣPBDE concentration=3.81 ng/g). This crucial breeding population of S. humboldti was not exposed to contaminants at levels detrimental to health and reproductive success; however, the identified concentrations of legacy and recently emerged toxicants underscore the need for temporal monitoring and diligence to protect this endangered species in the face of regional human population and industrial growth. These results also provided key reference values for spatial comparisons throughout the range of this species.
Herbicide resistant weeds have been observed since the early years of synthetic herbicide development in the 1950's and 1960's. Since that time there has been a consistent increase in the number of herbicide resistance cases and the impact of herbicide resistant (HR) weeds. While the nature of crop production varies widely around the world, herbicides have become a primary tool for weed control in most areas. Dependence on herbicides continues to increase as global populations migrate away from rural areas into cities and the agricultural labor force declines. This increased use of herbicides and concurrent selection pressure has resulted in a rise in cases of multiple resistance leaving some farmers with few or no herbicide options for certain weed infestations. Global population and economic forces drive many farmer choices regarding crop production and weed control. The challenge is how to insert best management practices into the decision making process while addressing various economic and regulatory needs. This review endeavors to provide a current overview of herbicide resistance challenges in the major crop production areas of the world and discusses some research initiatives designed to address portions of the problem.
The triazine herbicide atrazine (2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine) is one of the most used pesticides in North America. Atrazine is principally used for control of certain annual broadleaf and grass weeds, primarily in corn but also in sorghum, sugarcane, and, to a lesser extent, other crops and landscaping. Atrazine is found in many surface and ground waters in North America, and aquatic ecological effects are a possible concern for the regulatory and regulated communities. To address these concerns an expert panel (the Panel) was convened to conduct a comprehensive aquatic ecological risk assessment. This assessment was based on several newly suggested procedures and included exposure and hazard subcomponents as well as the overall risk assessment. The Panel determined that use of probabilistic risk assessment techniques was appropriate. Here, the results of this assessment are presented as a case study for these techniques. The environmental exposure assessment concentrated on monitoring data from Midwestern watersheds, the area of greatest atrazine use in North America. This analysis revealed that atrazine concentrations rarely exceed 20 μg/L in rivers and streams that were the main focus of the aquatic ecological risk assessment. Following storm runoff, biota in lower-order streams may be exposed to pulses of atrazine greater than 20 μg/L, but these exposures are short-lived. The assessment also considered exposures in lakes and reservoirs. The principal data set was developed by the U.S. Geological Survey, which monitored residues in 76 Midwestern reservoirs in 11 states in 1992-1993. Residue concentrations in some reservoirs were similar to those in streams but persisted longer. Atrazine residues were widespread in reservoirs (92% occurrence), and the 90th percentile of this exposure distribution for early June to July was about 5 μg/L. Mathematical simulation models of chemical fate were used to generalize the exposure analysis to other sites and to assess the potential effects of reduction in the application rates. Models were evaluated, modified, and calibrated against available monitoring data to validate that these models could predict atrazine runoff. PRZM-2 overpredicted atrazine concentrations by about an order of magnitude, whereas GLEAMS underpredicted by a factor of 2 to 5. Thus, exposure models were not used to extrapolate to other regions of atrazine use in this assessment. The effects assessment considered both freshwater and saltwater toxicity test results. Phytoplankton were the most sensitive organisms, followed, in decreasing order of sensitivity, by macrophytes, benthic invertebrates, zooplankton, and fish. Atrazine inhibits photophosphorylation but typically does not result in lethality or permanent cell damage in the short term. This characteristic of atrazine required a different model than typically used for understanding the potential impact in aquatic systems, where lethality or nonreversible effects are usually assumed. In addition, recovery of phytoplankton from exposure to 5 to 20 μg/L atrazine was demonstrated. In some mesocosm field experiments, phytoplankton and macrophytes were reduced after atrazine exposures greater than 20 μg/L. However, populations were quickly reestablished, even while atrazine residues persisted in the water. Effects in field studies were judged to be ecologically important only at exposures of 50 μg/L or greater. Mesocosm experiments did not reveal disruption of either ecosystem structure or function at atrazine concentrations typically encountered in the environment (generally 5 μg/L or less). Based on an integration of laboratory bioassay data, field effects studies, and environmental monitoring data from watersheds in high-use areas in the Midwestern United States, the Panel concluded that atrazine does not pose a significant risk to the aquatic environment. Although some inhibitory effects on algae, phytoplankton, or macrophyte production may occur in small streams vulnerable to agricultural runoff, these effects are likely to be transient, and quick recovery of the ecological system is expected. A subset of surface waters, principally small reservoirs in areas with intensive use of atrazine, may be at greater risk of exposure to atrazine. Therefore, it is recommended that site-specific risk assessments be conducted at these sites to assess possible ecological effects in the context of the uses to which these ecosystems are put and the effectiveness and cost-benefit aspect of any risk mitigation measures that may be applied.