Armando da Costa Duarte

University of Aveiro | UA · Department of Chemistry

Although the impacts of plastic pollution have long been recognized, the presence, pervasiveness, and ecotoxicological consequences of microplastic—i.e., plastic particles < 5 mm—contamination have only been explored over the last decade. Far less focus has been attributed to the role of these materials and, particularly, microplastics, as vectors...

Analysis of complex environmental matrices poses an extreme challenge for analytical chemists due to the vast number of known and unknown compounds, with very diverse chemical and physical properties. The need for a holistic characterisation of this complexity has sparked the development of effective tools to unravel the chemical composition of suc...

This study investigates the potential of MPs as carriers of pollutants as they can strengthen bioaccumulation of toxic metals on marine organisms. For the first time, the interaction of the metal palladium (Pd) with the widespread MPs, both with increasing concentrations in water environments from anthropogenic sources, was tested. Mytilus gallopro...

The main objective of this study is to perform an approximation on the microplastic pollution on a sandy beach in Costa Nova (Portugal), focused on longitudinal and cross-sectional transects. The results showed a scarce variability in data, with median concentrations ranging from 142 to 356 p/kg d.w. and 211 to 270 p/kg d.w. in cross-sectional and...

The impact of atmospheric particulate matter (PM), including PM2 [...]

Widespread contamination with microplastics (< 5 mm, MPs) has become an emerging global problem. Airborne microplastics and synthetic fibres contaminate the air we breathe, but their concentrations are highly influenced by sampling and analytical methodologies. This chapter reviews current pre-treatment and characterization techniques applied to ai...

Companion animals living in urban areas are exposed to environmental contaminants, which may include microplastics. A preliminary study was conducted by collecting postmortem samples from the internal tissue (lungs, ileum, liver, kidney, and blood clots) of 25 dogs (Canis familiaris) and 24 cats (Felis catus) living in an urban environment in Porto...

Cigarette butts (CBs) are non-biodegradable residues of synthetic origin, prevalent on beaches all over the world. The study evaluates discarded CBs on an intensely used urban beach, determining variations in physical and chemical characteristics. CBs collected were observed, classified, and visually separated according to a proposed scale of four...

Microplastics (MPs) are being recognized as an emergent route of contaminants to aquatic environments, which initially attracted the research interest on their interactions with organic pollutants. Lately, a turning point of attention is evident, with more published studies reporting the presence of metal(oid)s in plastics. This review assembles th...

Biobased and biodegradable plastic mulch film (aka, mulch biofilm) has emerged as a sustainable alternative to conventional plastic mulch films in agriculture, promising to reduce soil contamination with plastic residues through in situ biodegradation. However, current standards certifying biodegradable plastics cannot predict biodegradability in n...

The extraction of microplastics from organic-rich freshwater samples is challenging and limited information is available in the literature. This study aims at developing efficient methods for water volume reduction and organic matter removal in freshwater samples, while focusing on the reduction of the economic and environmental costs, maintaining...

The presence of aromatic compounds in rainwater is a matter of concern, mainly when the use of rainwater in buildings is intended. The present work aimed to assess the oxidation of a mixture of small aromatic compounds (benzoic, 3,5-dihydroxybenzoic and syringic acids) in rainwater by the UV/H2O2 process, and the possibility of its optimization by...

Microplastics have been found in fish, but most studies have focused on the digestive system without considering additional organs. Herein, the objective was to assess the presence of microplastics in internal organs (gills, guts, kidney, heart) of the Atlantic horse mackerel (Trachurus trachurus) captured of the coast of Portugal (Northeast Atlant...

Cyanide fishing is a method employed to capture marine fish alive on coral reefs. They are shipped to markets for human consumption in Southeast Asia, as well as to supply the marine aquarium trade worldwide. Although several techniques can be used to detect cyanide in reef fish, there is still no testing method that can be used to survey the whole...

The COVID-19 anthropause has impacted human activities and behaviour, resulting in substantial environmental and ecological changes. It has assisted in restoring the ecological systems by improving, for instance, air and water quality and decreasing the anthropogenic pressure on wildlife and natural environments. Notwithstanding, such improvements...

Microplastics are ubiquitous contaminants of freshwater ecosystems. However, few ecotoxicity assays have been conducted on freshwater organisms using environmentally relevant concentrations of virgin and weathered microplastics. This work assessed the adverse effects of virgin and artificially weathered fragments of polystyrene and polypropylene on...

The current understanding of water-soluble organic aerosol (OA) composition, sources, transformations, and effects is still limited to outdoor scenarios. However, the OA is also an important component of particulate matter indoors, whose complexity impairs a full structural and molecular identification. The current limited knowledge on indoor OA, a...

As a European Union (EU) member, Portugal must comply with reductions in plastic waste. In Portugal, the 330 items/100 m of beach litter, comprising up to 3.9 million pieces and of which 88% is plastic, is higher than the EU median (149 items/100 m) and must be reduced to 20 items/100 m (94%). Integrative measures are needed to reduce littering and...

Airborne microplastics and fibers in indoor and outdoor air may lead to human exposure through inhalation. Sampling was performed to determine concentrations of microplastics and fibers in the indoor air of living rooms of five houses in Aveiro, Portugal. Developments on contamination control measures allowed to reduce cross contamination (up to 98...

The ubiquity of microplastics raises issues regarding contamination control measures and laboratory practices. The objective was to adapt the use of counting chambers and plastic microplates on the ecotoxicity evaluation of microplastics. Counting chambers, originally used to quantify cells, can also be used to count high concentrations of micropla...

Many methods have been used to isolate and identify microplastics from biological matrices. In biological samples, Nile Red can stain undigested residues, such as fats, soaps, and gels formed during organic matter removal, hindering the identification of fluorescent microplastics (≥2 μm). Thus, adjustments on sample preparation (e.g., fat removal)...

Environmental sustainability is driving an intense search for “green materials”. Biobased plastics have emerged as a promising alternative. Their building blocks can now be obtained from diverse biomass, by-products, and organic residues due to the advances in biorefineries and bioprocessing technologies, decreasing the demand for fossil fuel resou...

Landfilling and illegal waste disposal have risen to deal with the COVID-19 potentially infectious waste, particularly in developing countries, which aggravates plastic pollution and inherent environmental threats to human and animal health. It is estimated that 3.5 million metric tonnes of masks (equivalent to 601 TIR containers) have been landfil...

Although landfills represent repositories for cumulative loading of plastic waste derived from households and industrial sectors, often seen as sinks, the contribution of these structures and their leachates as potential sources of microplastics to natural environments remains poorly covered. Microplastics discharged from these sites may pose great...

Microplastic (MPs) pollution has been recognized as a serious threat to marine environment with the growing use of plastics. There is no sufficient data on the extent and characteristics of MPs pollution in the beach sediments and sand in the Atlantic Ocean. The coastal area is one of the main tourist zones in Aveiro in Portugal, thus, impacted by...

The use of disposable face masks became essential to fight against the COVID-19 pandemic, resulting in an unprecedented rise in their production and, unfortunately, to a new form of environmental contamination due to improper disposal. Recent publications reported the abundance of COVID-19-related litter in several environments, wildlife interactio...

Atmospheric aerosol deposition (wet and dry) is an important source of macro and micronutrients (N, P, C, Si, and Fe) to the oceans. Most of the mass flux of air particles is made of fine mineral particles emitted from arid or semi-arid areas (e.g., deserts) and transported over long distances until deposition to the oceans. However, this atmospher...

Many governments have imposed the public use of face masks and they are now moving towards enforcing disposable masks to abate COVID-19 transmission. While disposable masks consistently provide higher protection, they also carry multiple environmental burdens, from greenhouse gases released during production to the landfilling and littering. Conver...

Nile Red staining enables visual identification and quantification of fluorescent particles as a proxy to microplastics at low cost and high throughput, including those of small sizes (≥2 μm), when preceded by proper natural organic matter removal, but providing no chemical characterization. On the other hand, micro-spectroscopy methods allow chemi...

To assess environmental risks related to the mobility and toxicity of AgNPs, the chemical availability of AgNPs and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs) in three agricultural soils was quantified in a pot experiment. Porewater collection and soil extractions with 0.01 M CaCl2, 0.4 M Glycine (pH 1.5) and 0.05 M NH4-EDTA were performed. The...

Water-soluble organic aerosols (OA) are an important component of air particles and one of the key drivers that impact both climate and human health. Understanding the processes involving water-soluble OA depends on how well the chemical composition of this aerosol component is decoded. Yet, obtaining detailed information faces several challenges,...

Sources contributing to specific concentration of microplastics and fibers are still not completely understood. This study aimed at assessing the concentrations of microplastics (2–5000 μm) and fibers (18–5667 μm) in three areas of distinct influences in the Douro river, Porto, Portugal: (i) a countryside area; (ii) a wastewater treatment effluent...

Microplastics contamination is widespread in the environment leading to the exposure of both humans and other biota. While most studies overemphasize direct toxicity of microplastics, particle concentrations, characteristics and exposure conditions being used in these assays needs to be taken into consideration. For instance, toxicity assays that u...

Reactive oxygen and nitrogen species (ROS and RNS) play a crucial role in biotic and abiotic processes. In the atmosphere, ROS/RNS are usually associated with air pollution. The ability of certain air particulate matter constituents to influence the formation and cycling of ROS/RNS at the atmosphere-biosphere-hydrosphere interfaces is important for...

Atmospheric fine particulate matter (PM2 [...]

Thermokarst lakes result from the thawing of ice-rich permafrost and are widespread across northern landscapes. These waters are strong emitters of methane, especially in permafrost peatland regions, where they are stained black by high concentrations of dissolved organic matter (DOM). In the present study, we aimed to structurally characterize the...

Airborne microplastics and microfibers are released from daily materials, contaminating both indoor and outdoor air. Sampling in Aveiro, Portugal, revealed concentrations of 6 fibers m⁻³, with more synthetic fibers found in outdoor than indoor (8.5% vs. 4.1%, n = 6), with variations in fiber characteristics between sampling periods. Suspected micro...

Widespread contamination of microplastics may lead to internalization in fish. This literature review from March 2019 to March 2020 details that a median of 60% of fish, belonging to 198 species captured in 24 countries, contain microplastics in their organs. Carnivores species ingested more microplastics than omnivores. Only 14% of fish were from...

Plastics and microplastics are ubiquitous contaminants in aquatic ecosystems. This critical review is the first attempt at analyzing sources, concentration, impacts and solutions of (micro)plastic litter in Portugal based on all currently available literature. We found that, besides sea-based sources (e.g. shipping, fishing), 5717 t of mismanaged w...

Plas­tics have be­come a se­vere trans­bound­ary threat to nat­ural ecosys­tems and hu­man health, with stud­ies pre­dict­ing a twofold in­crease in the num­ber of plas­tic de­bris (in­clud­ing mi­cro and nano-sized plas­tics) by 2030. How­ever, such pre­dic­tions will likely be ag­gra­vated by the ex­ces­sive use and con­sump­tion of sin­gle-use p...

Microplastics are widely distributed environmental contaminants. To understand their impacts on the environment and health, more high-quality results are needed. Since microplastics are present in every environment, including indoor air, proper precautions must be adopted in order to prevent contamination of samples and overestimation of environmen...

Scarce information is available concerning the presence of carbohydrates in rainwater. The existence of carbohydrates in bulk deposition at the town of Estarreja (Portugal), at industrial (I) and background (BG) locals, in winter and spring seasons 2016, was assessed. Seventeen carbohydrates and related compounds were identified: monosaccharides (r...

Microplastics became an unprecedented challenge and mapping their contamination all over the world is needed in order to establish baseline levels and identify the polymers in order to enhance adequate legislation and policy. The main objective of this study is to demonstrate the existence of microplastic pollution on three beaches on the coast of...

There has been an exponential interest in the occurrence and potential ecotoxicological consequences stemming from the growing prevalence of (micro)plastics in the environment. This has been especially evident by the increasing concern regarding the visible effects on marine ecosystems, with multiple local, regional, and trans-national initiatives...

Red mud-based inorganic polymer spheres were used as alternative pH regulators and process enhancers in sequencing batch anaerobic reactors treating cheese whey. This byproduct tends to quickly acidify under anaerobic conditions, and the common route to control pH and ensure suitable conditions for methane production involves the use of commercial...

Plastics have been on top of the political agenda in Europe and across the world to reduce plastic leakage and pollution. However, the COVID-19 pandemic has severely disrupted plastic reduction policies at the regional and national levels and induced disruptive changes in plastic waste management with potential for negative impacts in the environme...

Plastics are essential in society as a widely available and inexpensive material. Mismanagement of personal protective equipment (PPE) during COVID-19 pandemic, with a monthly estimated use of 129 billion face masks and 65 billion gloves globally, is resulting in widespread environmental contamination. This poses a risk to public health as a vector...

Multidimensional Analytical Techniques in Environmental Research is a comprehensive resource on the many multidimensional analytical strategies to qualitatively and quantitatively assess and map the organic and inorganic pollutants in complex atmospheric, water and soil matrices.

Beverages, often packaged in plastic, can be a source of microplastics in the human diet. In this study, an improved method for detection of microplastics in white wines capped with synthetic stoppers is explored. Visual quantification in the stereomicroscope or using Nile Red were excluded due to the small size of particles. Quantification in the...

Small microplastics (<1 mm) comprise a great fraction of microplastics (<5 mm) found in the environment and are often overlooked due to the constrains of transporting and filtering large volumes of water in grab samplings. The objective of this work was to determine the minimum volume for reliable quantification of small microplastics in the enviro...

Water-soluble organic matter (WSOM) in air particles has profound effects on climate and human health. At the heart of this environmental significance of WSOM lies a complex set of compounds, of which a major fraction still often remains undeciphered. Yet, not all environmental problems require delving into the molecular-level identification of WSO...

A INVENÇÃO CONCERNE UM DISPOSITIVO PARA A DETECÇÃO E QUANTIFICAÇÃO DE ALQUILFENÓIS EM AMOSTRAS LÍQUIDAS. A ARQUITECTURA FINAL DO DISPOSITIVO ASSENTA EM CAMADAS DE SILÍCIO (A), DIÓXIDO DE SILÍCIO (B), TITÂNIO (C) E OURO (F), QUE CONSTITUI O MICROTRANSÍSTOR ELECTRÓNICO. NESTE, SÃO DEPOSITADOS NANOTUBOS DE CARBONO DE PAREDE ÚNICA, SWCNTS, QUE ACTUAM C...

Automated count of Nile Red fluorescent microplastics allows fast and reliable quantification. However, factors involving staining, digital camera conditions and settings introduce variability to the results. The objective of this paper is to identify and propose solutions to these factors and improve on the previous MP-VAT script. While removal of...

Atmospheric particles, soils, sediments, and dissolved organic matter in aquatic compartments are among the most complex environmental matrices known. To a large extent, the complexity and heterogeneity of these matrices hinder the current understanding of the key processes in the environment. On the quest to mine the desired information, innovativ...

Separation and analysis methods have been evolving greatly over the last decades, nonetheless, regular single dimension techniques still struggle when dealing with the separation of more than a few dozen compounds. As such, samples exhibiting a higher complexity demand a much greater separation capacity. The addition of extra separation dimensions...

Coastal environments are highly contaminated with plastics of various sizes. In order to understand the distribution and factors influencing (micro)plastics contamination in the environment, sampling of a sandy beach in Costa Nova, Aveiro, Portugal, was conducted by collecting plastic particles and sediments for density separation in transects from...

Microplastics and microfibers can contaminate every matrix, including in the atmosphere, thus leading to incidental inhalation. However, concentrations of airborne synthetic particle in indoor and outdoor environments are not well understood due to the complexities of sampling, sample processing and identification. This work aims at producing a sim...

The impact of inhalable fine particulate matter (PM2.5, aerodynamic diameter < 2.5 µm) on public health is of great concern worldwide. Knowledge on their harmful effects are mainly due to studies carried out with whole air particles, being the contribution of their different fractions largely unknown. Herein, a set of urban PM2.5 samples were colle...

A new approach to preventive health is the study of the interdependency of human, animal and environmental health. Not only pathogens but also contaminants can travel between environmental compartments with potential consequences to health. Microplastics result from the intentional production or fragmentation of larger plastics and may produce dire...

Microplastics are ubiquitous environmental contaminants leading to inevitable human exposure. Even so, little is known about the effects of microplastics in human health. Thus, in this work we review the evidence for potential negative effects of microplastics in the human body, focusing on pathways of exposure and toxicity. Exposure may occur by i...

This paper presents baseline data of sediments characterization from Ria de Aveiro lagoon (Portugal). Twenty-two intertidal surface sediments were collected and analysed for their pseudo-total content of 25 major and trace elements and for their total content of PAHs (Sum16) and PCBs (Sum13). The fine fraction percentage and total organic carbon co...

Plastic pollution is generated by the unsustainable use and disposal of plastic products in modern society, threatening economies, ecosystems, and human health. Current clean-up strategies have attempted to mitigate the negative effects of plastic pollution but are unable to compete with increasing quantities of plastic entering the environment. Th...

Microplastics are widespread contaminants in the environment. However, most identification protocols rely on long and subjective visual counting, which could be improved using staining dyes. Thus, the objective of this work is to identify the best staining dye protocol and create an objective and quick automated counting software for microplastics....

Natural organic matter may confound the detection of microplastics, requiring a removal step. However, most available protocols are long and lack information on removal efficiency and polymer degradation. Thus, we have determined the digestion efficiency (%) for a pool of organic matter (algae, driftwood, feathers, fish muscle, paraffin, palm oil)...

The present work aimed to assess the sorption capacity of the common white bean (Phaseolus vulgaris L.) to remove Zn(II) from rainwater, rendering it suitable for use in buildings, and the efficiency of the process was evaluated for two initial Zn(II) concentrations, representing high (100 μg L-1) and very high (500 μg L-1) levels of Zn(II) in rain...

Chromatography is the separation method of choice in most laboratories worldwide. Nonetheless, the increasing need to decode complex samples has created a demand for better separation skills. The addition of extra separation dimensions to a conventional liquid chromatography system was one of the ways to answer to this demand. Although very common...

Seaweeds, which have been widely used for human consumption, are considered a potential source of biological compounds, where enzyme-assisted extraction can be an efficient method to obtain multifunctional extracts. Chemical characterization of Sargassum muticum and Osmundea pinnatifida extracts obtained by Alcalase and Viscozyme assisted extractio...

The objectives of this research were to quantify the impact of organic matter content, soil pH and moisture content on the dissolution rate and solubility of copper oxide nanoparticles (CuO NPs) in soil, and to develop an empirical model to predict the dissolution kinetics of CuO NPs in soil. CuO NPs were dosed into standard LUFA soils with various...

Urban soils quality may be severely affected by polycyclic aromatic hydrocarbons (PAHs) contamination, as is the case of Lisbon (Portugal). However, to conduct a risk assessment analysis in an urban area can be a very difficult task due to the patchy nature and heterogeneity of these soils. Thus, the present study aims to provide an example on how...

Microplastics are persistent contaminants accumulating in the environment. Aquatic ecosystems have been studied worldwide, revealing ubiquitous contamination with microplastics. Microalgae, one of the most important primary producers in aquatic ecosystems, could suffer from microplastic contamination, leading to larger impacts on aquatic food webs....

Environmental compartments are being enriched with myriads of nanoparticles (NPs) known for their unique physicochemical characteristics. Plants are sessile in nature and have greater chance to interact with environmental NPs. Oxidative stress, a condition of imbalance between the pace of reactive oxygen species (ROS) generation and its metabolism,...