Chemical and morpho-structural characterization of atmospheric aerosol (PM10 and PM2.5) in a city of São Paulo state, Brazil.

To access the sources of air pollutants is crucial to control atmospheric pollution in urban areas, minimizing human exposure. Particulate matter is a pollutant of great concern making its chemical and morpho-structural characterization of enormous importance. The present work aims at the characterization of atmospheric PM10 and PM2.5. Data of the aerosol mass concentration was correlated by multivariate analysis with water-soluble ion fraction composition accessed by ion chromatography (IC), as well as with meteorological information and air mass backward trajectories. The gravimetric analysis presented average values 3 to 4 times higher than the guide values recommended by the World Health Organization (WHO). A morpho-structural analysis by SEM/FEG coupled to EDS was also carried out identifying the coarse fraction elements from minerals and from soil resuspension organic spherical particles that originated from combustion processes as well as Ti, associated with long-distance transportation. In the fine fraction, Zn with origin probably in tires and vehicle brakes was found. These origins were confirmed by the air masses' backward trajectories obtained by the HYSPLIT model (NOAA). This study contributes to a better understanding of the complex composition of the particulate material in the atmosphere of Araraquara City, resulting from the combination of local and long-distance sources, and serves as a basis for the comparison with future studies related to the air quality at this and other regions in Brazil and in the world.

Low-cost Gent type sampler constructed for urban atmospheric aerosol sampling.

The importance of studying the atmospheric pollution due to its effects on human health and other ecosystems, the inexistence of national production of equipment for air sample collection, and the high cost of the imported equipment (especially in developing countries) led the authors of the present work to construct a low-cost Gent type sampler. The construction of the sampler was carried out by combining low-cost materials with good mechanical strength (such as nylon 6.0), hydraulic piping PVC, and the use of a 3D printer. The innovation of the present work is the employment of a 3D printer using ABS polymer to create the grids that cannot be machined. In addition to the sampler, the system is composed of a vacuum pump, a gas meter, and a rotameter. The total cost of the sampling system amounted at about 1200 USD, and the cost of the manufactured Gent type sampler did not reach 100 USD. The results obtained while using this set for sampling atmospheric aerosol for a period of 11 months were compared with the mass concentration of PM10 obtained from the official environmental company, CETESB of São Paulo State, Brazil, showing good correlation with those from CETESB - which confirmed its effectiveness and suitability for use. The low cost, easy operation, and versatility of the built Gent type sampler enable its use for scientific and academic purposes. The equipment can be useful in environmental monitoring networks, in low-income regions, and as an instrument for environmental education used in universities.

Effects of biostimulation by sugarcane bagasse and coffee grounds on sewage sludges, focusing agricultural use: Microbial characterization, respirometric assessment and toxicity reduction.

Sewage sludge (SS) exhibits a relevant agronomic potential due to the high content of organic matter and nutrients. However, the presence of several toxic substances can prevent its agricultural application. This study evaluated if the incorporation of stimulating agents (coffee grounds and sugarcane bagasse) could contribute to an effective increase of the SS biodegradability in order to decrease its toxicity. The samples were prepared mixing aerobic or anaerobic sludge with soil, soil and bagasse, and soil and coffee grounds. Respirometric tests showed that stimulating agents enhanced the CO2 production. However, in terms of biodegradation efficiency, more satisfactory results were verified for the anaerobic SS, especially when mixed with coffee grounds. The biodegradation also favored the SS sanitization, eliminating the Enterobacteria. For baseline toxicity (Microtox with Aliivibrio fischeri) and phytotoxicity (Lactuca sativa), all the initial samples showed higher effects. Nevertheless, after the biodegradation, this toxicity was significantly decreased and the best results were obtained for the mixtures containing only soil and sludge. For the AREc32 assay (NRF2 mediated oxidative stress response), although a very weak response was observed, this effect was attenuated for the aerobic SS or completely eliminated for the anaerobic SS after the biodegradation. Thus, even though the use of biostimulation agents during the biodegradation led to an enhancement of microbial respiration, their incorporation to the samples do not seem to interfere in the decrease of the toxic potential of the studied SSs. However, the SS biodegradation in aerobiosis was crucial for toxicity reduction and to accelerate its maturity.

Occurrence of flame retardants in landfills: A case study in Brazil.

Huge amounts of waste containing flame retardants reach landfills annually, which can result in environmental contamination if this type of solid residues is not properly managed. This study presents data concerning the occurrence of organophosphorus flame retardants (OPFRs), polybrominated diphenyl ethers (PBDEs) and new brominated flame retardants (NBFRs) in soil, dust, leachate and well water samples from a landfill in Brazil. Samples were collected in different points of the landfill site, including offices, concierge, electronic waste storage area, bulk waste storage area, a place where a recycling cooperative operates, leachate pound and wells. Most of the flame retardants (FRs) were quantified in soil samples (up to 2500 ng g-1). The tris(2-chloroisopropyl) phosphate (TCIPP) and tris(1,3-dichloroisopropyl) phosphate (TDCIPP) were present at the highest levels in the site where bulk waste was disposed in the open air. The most abundant brominated FRs in soil samples were BDE-99, BDE-209, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and the highest levels were observed in the samples collected from the electronic waste storage area. Concerning dust samples, the highest levels of brominated FRs were observed in the electronic waste storage area, while the highest levels of OPFRs were observed in the landfill office. TCIPP, TDCIPP and tris(2-choroethyl) phosphate (TCEP) were quantified in the well water sample collected downstream the bulk waste area. Finally, six OPFRs were quantified in leachate at concentrations ranging from 14 to 965 ng L-1. In conclusion, this study demonstrates that an improper management of wastes containing FRs in landfills can potentially contaminate the surrounding environment and groundwater.

QuEChERS-Based Method for Pesticides Analysis in Adipose Tissue Associated with Rat Ovaries.

The concomitant exposure to low doses of various pesticides is one of the most relevant issues in human toxicology today. An experimental toxicology study was developed to evaluate the effects of this type of exposure on the reproductive capacity of females of three species of rats that were exposed to mixtures of dicofol, dieldrin, endosulfan and permethrin at low doses (LOAEL and NOAEL). In this context, we have developed a method for determining pesticides in adipose tissue (0.5 g, 49% lipid) associated with the ovaries, based on the QuEChERS (quick, easy, cheap, effective, rugged and safe) strategy. The method quantification limit (LOQ) was 0.5 mg/kg for dicofol and permethrin, 0.05 mg/kg for endosulfan and dieldrin and 0.2 mg/kg for diclorobenzophenone. Mean recoveries ranged from 75% to 93% with a relative standard deviation <13%. The unspecific selectivity (matrix effect) indicates the mandatory use of analytical curves constructed on the matrix extract. All the analyzed samples (53 adipose tissue associated to ovaries) showed residues of dichlorobenzophenone + dicofol, dieldrin and cis-permethrin while trans-permethrin were detected in 40% of the samples but were below the LOQ. The data indicated the bioaccumulation characteristics of these substances.

Distribution of butyltin compounds in Brazil's southern and southeastern estuarine ecosystems: assessment of spatial scale and compartments.

Butyltin compounds (BTs), including tributyltin (TBT) and its degradation products, dibutyltin and monobutyltin, have been found in a diversity of aquatic systems and causing toxic effects in target and nontarget organisms. They enter in coastal systems through different sources (as antifouling paints, industrial effluents, etc.) where they interact with biotic and abiotic components, and their distribution is commonly determined by the morphological and hydrodynamic conditions of the coastal systems. In this study, we discuss the contamination by BTs on a spatial scale (eight estuaries with three subareas each) and in different compartments of the estuaries (sediments, suspended particulate matter (SPM), and estuarine catfish tissues (liver and gills). Lower concentrations of BTs were found in the sediments (n.d. to 338 ng g(-1)) in comparison to studies before a ban of TBT in antifouling paints was enacted, mostly indicating an old input or preservation related with sediment properties and composition. For SPM samples (n.d. to 175 ng L(-1)) as well as in fish tissues (n.d. to 1426 ng g(-1)), the presence of these compounds was frequent, especially in the fish due to their movement throughout the estuaries and the potential to assess point sources of BTs. These results indicate that BTs persist in the environment, with variation in amounts between investigated estuaries and even at locations inside the same estuary, because of ideal preservation conditions, transport to remote areas, and input from different sources.

The occurrence of UV filters in natural and drinking water in São Paulo State (Brazil).

Ultraviolet (UV) filters are widely used in the formulation of personal care products (PCPs) to prevent damage to the skin, lips, and hair caused by excessive UV radiation. Therefore, large amounts of these substances are released daily into the aquatic environment through either recreational activities or the release of domestic sewage. The concern regarding the presence of such substances in the environment and the exposure of aquatic organisms is based on their potential for bioaccumulation and their potential as endocrine disruptors. Although there are several reports regarding the occurrence and fate of UV filters in the aquatic environment, these compounds are still overlooked in tropical areas. In this study, we investigated the occurrence of the organic UV filters benzophenone-3 (BP-3), ethylhexyl salicylate (ES), ethylhexyl methoxycinnamate (EHMC), and octocrylene (OC) in six water treatment plants in various cities in Southeast Brazil over a period of 6 months to 1 year. All of the UV filters studied were detected at some time during the sampling period; however, only EHMC and BP-3 were found in quantifiable concentrations, ranging from 55 to 101 and 18 to 115 ng L(-1), respectively. Seasonal variation of BP-3 was most clearly noticed in the water treatment plant in Araraquara, São Paulo, where sampling was performed for 12 months. BP-3 was not quantifiable in winter but was quantifiable in summer. The levels of BP-3 were in the same range in raw, treated and chlorinated water, indicating that the compound was not removed by the water treatment process.

Determination of estrogenic mycotoxins in environmental water samples by low-toxicity dispersive liquid-liquid microextraction and liquid chromatography-tandem mass spectrometry.

A novel, simple, rapid and eco-friendly method based on dispersive liquid-liquid microextraction using a bromosolvent was developed to determine six estrogenic mycotoxins (zearalenone, zearalanone, α-zearalanol, ß-zearalanol, α-zearalenol and ß-zearalenol) in water samples by liquid chromatography-electrospray ionization tandem mass spectrometry in the negative mode (LC-ESI-MS/MS). The optimal conditions for this method include the use of 100 µL bromocyclohexane as an extraction solvent (using a non-dispersion solvent), 10 mL of aqueous sample (adjusted to pH 4), a vortex extraction time of 2 min, centrifugation for 10 min at 3500 rpm and no ionic strength adjustment. The calibration function was linear and was verified by applying the Mandel fitting test with a 95% confidence level. No matrix effect was observed. According to the relative standard deviations (RSDs), the precision was better than 13% for the repeatability and intermediate precision. The average recoveries of the spiked compounds ranged from 81 to 118%. The method limits of detection (LOD) and quantification (LOQ) considering a 125-fold pre-concentration step were 4-20 and 8-40 ng L(-1), respectively. Next, the method was applied to the analysis of the environmental aqueous samples, demonstrating the presence of ß-zearalanol and zearalanone in the river water samples.

Method validation using weighted linear regression models for quantification of UV filters in water samples.

This paper describes the validation of a method consisting of solid-phase extraction followed by gas chromatography-tandem mass spectrometry for the analysis of the ultraviolet (UV) filters benzophenone-3, ethylhexyl salicylate, ethylhexyl methoxycinnamate and octocrylene. The method validation criteria included evaluation of selectivity, analytical curve, trueness, precision, limits of detection and limits of quantification. The non-weighted linear regression model has traditionally been used for calibration, but it is not necessarily the optimal model in all cases. Because the assumption of homoscedasticity was not met for the analytical data in this work, a weighted least squares linear regression was used for the calibration method. The evaluated analytical parameters were satisfactory for the analytes and showed recoveries at four fortification levels between 62% and 107%, with relative standard deviations less than 14%. The detection limits ranged from 7.6 to 24.1 ng L(-1). The proposed method was used to determine the amount of UV filters in water samples from water treatment plants in Araraquara and Jau in São Paulo, Brazil.

Bioaccumulation of butyltins and liver damage in the demersal fish Cathorops spixii (Siluriformes, Ariidae).

The toxicity of butyltin compounds (BTs), mainly tributyltin (TBT), has been reported in different organisms. However, such an analysis in fish after field exposure with reference to the related biomarkers has not been commonly observed in the literature. This study presents the uptake of BTs in the liver of a neotropical marine catfish Cathorops spixii in Paranagua Bay, an important estuarine system located in southern Brazil. Two different areas, close to and distant from the harbor, were used for chemical analysis evaluation of hepatotoxicity through genetic, enzymatic, and histopathological biomarkers. The presence of polycyclic aromatic hydrocarbons in bile was also considered as a biomarker. The results showed a significant relationship between TBT levels and the inhibition of biotransformation enzymes and high occurrence of melanomacrophages in fish collected close to the harbor site. These effects were linked to the absence of TBT metabolites in the liver. In the second site, the presence of DBT was associated with an increase in EROD and GST activity. The larger amount of DNA damage as well as the highest oxidative stress was noted in fish from the less TBT-polluted area, where DBT and bile PAHs occurred. These findings showed different impact levels due to or increased by the chronic exposure of biota to BTs.

Intrauterine exposure to diesel exhaust diminishes adult ovarian reserve.

OBJECTIVE: To analyze ovarian and uterine morphologic changes resulting from intrauterine and postnatal exposure to diesel exhaust. DESIGN: Crossover study. Experimental groups: intrauterine and postnatal clean air exposure; intrauterine exposure to diesel only; postnatal exposure to diesel only; and intrauterine and postnatal exposure to diesel. SETTING: Laboratory of Experimental Air Pollution. ANIMAL(S): Swiss mice. INTERVENTION(S): Mice exposed to diesel exhaust with doses that correspond to the daily average PM2.5 levels (fine particles in the ambient air 2.5 µm or less in size) reported by the World Health Organization. MAIN OUTCOME MEASURE(S): Morphometric analyses of the ovaries and uterus were performed to define the relative area occupied by follicles, corpus luteum, and stroma and the proportionate area of glands, epithelial layer, and stroma within the uterine endometrium. RESULT(S): A significant reduction in the proportion of primordial follicles was observed in intrauterine-exposed animals, those exposed during the postnatal period, and in animals exposed during both phases. Primary follicle proportion was reduced in animals exposed during pregnancy. No significant changes were detected in uterine morphology. CONCLUSION(S): Intrauterine exposure to acceptable levels of diesel exhaust compromises the reproductive potential of female mice, diminishing ovarian reserve when sexual maturity is achieved. This effect could increase the risk of premature menopause. The findings raise concern about current environmental guidelines for diesel exposure, warranting more careful examination of this issue in humans by regulatory authorities.

Organotins: a review of their reproductive toxicity, biochemistry, and environmental fate.

The review purposes are to (1) evaluate the experimental evidence for adverse effects on reproduction and metabolism and (2) identify the current knowledge of analytical procedures, biochemistry and environmental aspects relating to organotins. Organotins are pollutants that are used as biocides in antifouling paints. They produce endocrine-disrupting effects in mollusks, such as imposex. In rodents, organotin exposure induces developmental and reproductive toxicity as well as alteration of metabolic homeostasis through its action as an obesogen. The adverse effects that appear in rodents have raised concerns about organotins' potential health risk to humans in relation to organotin exposure. At present, triorganotin, such as tributyltin, have been demonstrated to produce imposex, and mammalian reproductive and metabolic toxicity. For most mammals, triorganotin exposure predominantly occurs through the ingestion, and this compound can cross the placenta. With these risks in mind, it is important to improve our knowledge of organotins' effects on environmental health.

A rapid, environmentally friendly, and reliable method for pesticide analysis in high-fat samples.

This report describes the development and validation of a simple, rapid, and efficient method in which solid-phase extraction followed by analysis in a gas chromatograph equipped with an electron capture detector (SPE-GC-ECD) is used for the simultaneous determination of dicofol, dieldrin, endosulfan, and permethrin in rat adipose tissue. This study targeted pesticides for which controversies exist regarding the harm that they may cause to humans, such as endocrine disruption or cancer, and that have also been found in recent years in vegetables consumed by the Brazilian population. The analytical procedure was optimised for SPE extraction and for GC-ECD conditions. The optimised method includes the extraction of the samples with n-hexane followed by an SPE procedure in which deactivated neutral alumina cartridges are used as the sorbent and a mixture of n-hexane:dichloromethane is used for elution. Recovery studies with spiked samples were used to evaluate the method's efficiency. Mean recoveries ranged from 75% to 119% with relative standard deviations (RSD)<19%. Quantification limits (LOQs) were 0.05 mg kg(-1) for dieldrin and endosulfan and 0.5 mg kg(-1) for dicofol and permethrin. The matrix effect was pronounced for all of the pesticides studied and ranged from 26% to 49%. In comparison to other related methods, this method requires less time and solvent and allows for rapid isolation of the target analytes with high selectivity. This method therefore allows for the screening of numerous samples and can also be used for routine analyses.

Burnt sugarcane harvesting: particulate matter exposure and the effects on lung function, oxidative stress, and urinary 1-hydroxypyrene.

Non-mechanised sugarcane harvesting preceded by burning exposes workers and the people of neighbouring towns to high concentrations of pollutants. This study was aimed to evaluate the respiratory symptoms, lung function and oxidative stress markers in sugarcane workers and the residents of Mendonça, an agricultural town in Brazil, during the non-harvesting and harvesting periods and to assess the population and individual exposures to fine particulate matter (PM(2.5)). Sugarcane workers and healthy volunteers were evaluated with two respiratory symptom questionnaires, spirometry, urinary 1-hydroxypyrene levels, and the measurement of antioxidant enzymes and plasma malonaldehyde during the non-harvesting and harvesting periods. The environmental assessment was determined from PM(2.5) concentration. PM(2.5) level increased from 8 µg/m³ during the non-harvesting period to 23.5 µg/m³ in the town and 61 µg/m³ on the plantations during the harvesting period. Wheezing, coughing, sneezing, and breathlessness increased significantly in both groups during the harvesting period, but more markedly in workers. A decrease in lung function and antioxidant enzyme activity was observed in both populations during harvesting; this decrease was greater among the sugarcane workers. The urinary 1-hydroxypyrene levels only increased in the sugarcane workers during the harvesting period. The malonaldehyde levels were elevated in both groups, with a higher increase observed in the workers. This research demonstrates the exposure of sugarcane workers and the inhabitants of a neighbouring town to high PM(2.5) concentrations during the sugarcane harvest period. This exposure was higher among the sugarcane workers, as illustrated by both higher PM(2.5) concentrations in the sugarcane fields and higher urinary 1-hydroxypyrene levels in the volunteers in this group. The higher incidence of respiratory symptoms, greater decrease in lung function and more marked elevation of oxidative stress markers among the sugarcane workers during the harvest confirms the greater effect magnitude in this population and a dose-dependent relationship between pollution and the observed effects.

An overview of biodiesel soil pollution: data based on cytotoxicity and genotoxicity assessments.

Biodiesel production has received considerable attention in the recent past as a nonpolluting fuel. However, this assertion has been based on its biodegradability and reduction in exhaust emissions. Assessments of water and soil biodiesel pollution are still limited. Spill simulation with biodiesel and their diesel blends in soils were carried out, aiming at analyzing their cytotoxic and genotoxic potentials. While the cytotoxicity observed may be related to diesel contaminants, the genotoxic and mutagenic effects can be ascribed to biodiesel pollutants. Thus, taking into account that our data stressed harmful effects on organisms exposed to biodiesel-polluted soils, the designation of this biofuel as an environmental-friendly fuel should be carefully reviewed to assure environmental quality.

Cytotoxicity of water-soluble fraction from biodiesel and its diesel blends to human cell lines.

The designation of biodiesel as a green fuel has increased its commercialization and use, making its fate in the environment a matter of concern. Fuel spills constitute a major source of aquatic pollution and, like diesel spills, biodiesel can produce adverse effects on aquatic environments, animals and humans. The present study assessed cytotoxic effects of water systems contaminated with neat biodiesel and its diesel blends by means of different procedures on human T cell leukemia (Jurkat) and human hepatocellular carcinoma (HepG2) cells [detection of changes in mitochondrial membrane potential (ΔΨ(m)) using tetramethylrhodamine ethyl ester (TMRE), apoptosis recognition by Annexin V and impedance real-time cell analyzer (xCELLigence™ system)]. The data obtained showed concordance across the different bioassays, with cytotoxic effects observed as a dose-dependent response only for waters contaminated with pure diesel (D100) and B5 blend, which is characterized by a mixture of 95% diesel and 5% biodiesel. The data can also lead us to hypothesize that diesel accounts for the harmful effects observed, and that biodiesel does not worsen the impacts caused by diesel pollution.

Re-examination of the anion derivatives of isoflavones by radical fragmentation in negative electrospray ionization tandem mass spectrometry: experimental and computational studies.

This paper reports theoretical and experimental studies of gas-phase fragmentation reactions of four naturally occurring isoflavones. The samples were analyzed in negative ion mode by direct infusion in ESI-QqQ, ESI-QqTOF and ESI-Orbitrap systems. The MS/MS and MS(n) spectra are in agreement with the fragmentation proposals and high-resolution analyses have confirmed the formulae for each ion observed. As expected, compounds with methoxyl aromatic substitution have showed a radical elimination of •CH(3) as the main fragmentation pathway. A second radical loss (•H) occurs as previously observed for compounds which exhibit a previous homolytic •CH(3) cleavage (radical anion) and involves radical resonance to stabilize the anion formed. However, in this study we suggest another mechanism for the formation of the main ions, on the basis of the enthalpies for each species. Compounds without methoxy substituent dissociate at the highest energies and exhibit the deprotonated molecule as the most intense ion. Finally, energy-resolved experiments were carried out to give more details about the gas-phase dissociation reaction of the isoflavones and the results are in agreement with the theoretical approaches.

Mutagenic activity of airborne particulate matter (PM10) in a sugarcane farming area (Araraquara city, southeast Brazil).

Brazil contains 25% of the total land planted with sugarcane in the world and is thus one of the major producers. The annual burning of sugarcane fields prior to harvesting emits huge amounts of pyrogenic particles. Biomass burning is an important primary and secondary source of aerosol particles. The presence of carbonaceous particles in the inhalable size range makes it important to study this fraction in view of the possible effects on human health and the climate. In this study, the mutagenic activity associated with inhalable airborne particulate matter (PM(10)) collected on air filters in a sugarcane-growing area near the city of Araraquara (SE Brazil) was determined. The extracts were dissolved in dimethylsulfoxide and tested for mutagenicity by the Ames plate incorporation test with Salmonella typhimurium YG1024 in the presence and absence of the S9 mixture. To assess the association between mutagenicity and PM(10), samples were collected in sugarcane harvesting and non-harvesting periods of the year. Significant mutagenicity was detected in organic solvent extracts of all samples, with differences between the two periods. The highest values of mutagenic potency (13.45 and 5.72 revertants/m(3) of air in the absence and presence of the S9 mixture, respectively) were observed during the harvest. In this period, a Teflon™-coated glass-fiber air filter trapped 67.0 µg of particulate matter per m(3) of air. In the non-harvest period, on the same type of filter, only 20.9 µg of particulate matter was found per m(3). The mutagenic potencies at this time were 1.30 and 1.04 revertants/m(3) of air, in the absence and presence of the S9 mixture, respectively. Period, concentration of PM(10) and mutagenicity were associated with each other. For routine monitoring of mutagenicity in the atmosphere, the use of YG1024 tester strain without metabolic activation (S9) is recommended.

Speciation of butyltin derivatives in surface sediments of three southern Brazilian harbors.

For the first time, organotin compounds were determined in surface sediment samples collected from São Francisco do Sul, Itajaí-Navegantes and Imbituba Harbors, located in Santa Catarina State, Brazil. Butyltins (BTs) were determined by gas chromatography with a pulsed flame photometric detector (GC-PFPD) after being modified using the Grignard derivatization method. The concentrations of BTs derivatives ranged from n.d. to 1136.6 ng (Sn) g(-1) of dry weight (dw) sediment for tributyltin (TBT), n.d. to 394.4 ng (Sn)g(-1) dw for dibutyltin (DBT) and n.d. to 312.2 ng (Sn) g(-1) dw for monobutyltin (MBT). The highest concentration of total BTs was found at the Itajaí-Açu River dockyard, indicating intense inputs of antifouling paints to the environment. The relative difference in the BTs levels is a particular characteristic of sediments from harbors and may be related to the shipyards and the boat traffic which still use TBT-based antifouling paints.

Integrated analysis of halogenated organic pollutants in sub-millilitre volumes of venous and umbilical cord blood sera.

A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs, polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD) and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000 microL were extracted and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction of small volumes (> or = 300 microL) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability ranged from 0.1-14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n = 73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned halogenated pollutants using this method and the results are briefly described.