Pesticide residues in European sediments: A significant concern for the aquatic systems?

The presence of pesticide residues in waterbed sediments poses a significant concern for aquatic ecosystems' health. This study examined pesticide contamination in sediments of 38 water bodies, embedded in agricultural-dominated regions, across eight European countries. Three indicators were targeted: occurrence, type, and concentrations of multiple pesticide residues in sediments. 196 pesticide residues (including degradation products) were tested in the sediment samples. The analytical results showed that only one sample was 'pesticide-free', three samples contained a single pesticide residue, and the remaining 34 samples contained mixtures of residues. Overall, 99 different residues were found in the sediments, with a maximum of 48 in a single sample. Twenty-seven out of the 99 detected residues were not approved for agricultural use at the time of sampling. The numbers of detected residues and pesticide levels varied among countries. AMPA, glyphosate and DDTs were the most common residues in sediment samples with frequencies of 76, 61, and 52%, respectively. The sediments from the Czech Republic had the highest pesticide concentrations, with total pesticide concentrations ranging between 600 and 1200 μg kg-1. The lowest total pesticide concentrations were found in Slovenia, Switzerland, Croatia, and Denmark, ranging between 80 and 120 μg kg-1. Sediments presented a mix of non-persistent and persistent compounds. Twelve of the detected pesticides are very persistent/stable in sediments, raising concerns about the long-term impacts of pesticides. Our study on the distribution of pesticide residues in European sediments provides valuable insights into the extent of pesticide contamination and possible risks of pesticides to water bodies' health. It also underlines the need for monitoring, research, and policy efforts to mitigate the impacts of pesticides, and to evaluate potential risks of re-use of dredged sediments.

Multi-residue determination of biocides in dairy products and slurry feed using QuEChERS extraction and liquid chromatography combined with high resolution mass spectrometry (LC-ESI-QOrbitrap™-MS)

Given that the determination of biocides in food and feed is currently not routinely done, more information on these compounds is useful for consumer's safety. This work describes a sensitive and reliable method for quantitative analysis of a wide range of biocides in dairy products and slurry feed. The method comprises acetate-buffered QuEChERS extraction without clean-up. Analyses were performed by LC-Q-Orbitrap™-MS and a full-scan acquisition event without fragmentation was followed by five fragmentation events (data-independent acquisition-DIA). The quantitative validation was performed according to SANTE/11312/2021 at 10, 50 and 200 ng g-1 spiking levels, and the results showed that the vast majority of the compounds met the criteria for trueness and precision. The LOQ was 10 ng g-1 for the majority of biocides depending on the matrix. The method was successfully applied to quantify biocides in dairy products and feed.

Assessing pesticide residues occurrence and risks in water systems: A Pan-European and Argentina perspective

Freshwater ecosystems face a particularly high risk of biodiversity loss compared to marine and terrestrial systems. The use of pesticides in agricultural fields is recognized as a relevant stressor for freshwater environments, exerting a negative impact worldwide on the overall status and health of the freshwater communities. In the present work, part of the Horizon 2020 funded SPRINT project, the occurrence of 193 pesticide residues was investigated in 64 small water bodies of distinct typology (creeks, streams, channels, ditches, rivers, lakes, ponds and reservoirs), located in regions with high agricultural activity in 10 European countries and in Argentina. Mixtures of pesticide residues were detected in all water bodies (20, median; 8-40 min-max). Total pesticide levels found ranged between 6.89 and 5860 ng/L, highlighting herbicides as the dominant type of pesticides. Glyphosate was the compound with the highest median concentration followed by 2,4-D and MCPA, and in a lower degree by dimethomorph, fluopicolide, prothioconazole and metolachlor(-S). Argentina was the site with the highest total pesticide concentration in water bodies followed by The Netherlands, Portugal and France. One or more pesticides exceeded the threshold values established in the European Water Framework Directive for surface water in 9 out of 11 case study sites (CSS), and the total pesticide concentration surpassed the reference value of 500 ng/L in 8 CSS. Although only 5 % (bifenthrin, dieldrin, fipronil sulfone, permethrin, and terbutryn) of the individual pesticides denoted high risk (RQ > 1), the ratios estimated for pesticide mixtures suggested potential environmental risk in the aquatic compartment studied.

Innovative analytical methodologies for characterizing chemical exposure with a view to next-generation risk assessment

The chemical burden on the environment and human population is increasing. Consequently, regulatory risk assessment must keep pace to manage, reduce, and prevent adverse impacts on human and environmental health associated with hazardous chemicals. Surveillance of chemicals of known, emerging, or potential future concern, entering the environment-food-human continuum is needed to document the reality of risks posed by chemicals on ecosystem and human health from a one health perspective, feed into early warning systems and support public policies for exposure mitigation provisions and safe and sustainable by design strategies. The use of less-conventional sampling strategies and integration of full-scan, high-resolution mass spectrometry and effect-directed analysis in environmental and human monitoring programmes have the potential to enhance the screening and identification of a wider range of chemicals of known, emerging or potential future concern. Here, we outline the key needs and recommendations identified within the European Partnership for Assessment of Risks from Chemicals (PARC) project for leveraging these innovative methodologies to support the development of next-generation chemical risk assessment.

Hidden risk of terrestrial food chain contamination from organochlorine insecticides in a vegetable cultivation area of Northwest Bangladesh

Organochlorine insecticide (OCI) exposures in terrestrial food chains from historical or current applications were studied in a vegetable production area in northwest Bangladesh. A total of 57 subsoil, 57 topsoil, and 57 vegetable samples, as well as 30 cow's milk samples, were collected from 57 farms. Multiple OCI residues were detected using GC-MS/MS with modified QuEChERS in 20 % of subsoils, 21 % of topsoils, 23 % of vegetables, and 7 % of cow's milk samples. Diversified OCI residues were detected in subsoils (17 residues with a concentration of 179.15 ± 148.61 μg kg-1) rather than in topsoils (3 DDT residues with a concentration of 25.76 ± 20.19 μg kg-1). Isomeric ratios indicate intensive historical applications of OCIs. According to Dutch and Chinese standards, the lower concentrations of individual OCI residues in the soil indicate negligible to slight soil pollution, assuming local farmers follow local pesticide use regulations. However, a maximum of 78.24 μg kg-1 ΣAldrines and 35.57 μg kg-1 ΣHCHs were detected (1-4 residues) in 60 % of brinjal, 28 % of cucumber, 29 % of sponge gourd, and 20 % of lady's finger samples, which could be a result of either historical or current OCI applications, or both. A strong positive correlation between aldrines in subsoils and cucurbit vegetables indicates greater bioaccumulation. Cow milk samples contained up to 6.96 μg kg-1 ΣDDTs, which resulted either from rationing contaminated vegetables or grazing on contaminated land. Individual OCI in both vegetables and cow's milk was below the respective maximum residue limits of US and FAO/WHO CODEX and poses little or no risk to human health. However, combined exposure to multiple pesticides could increase human health risks. A cumulative health risk assessment of multiple pesticide residues is suggested to assess the suitability of those soils for cultivation and grazing, as well as the safety of vegetables and cow's milk for human consumption.

Assessment of exposure to pesticides: residues in 24 h duplicate diets versus their metabolites in 24 h urine using suspect screening and target analysis

Human biomonitoring can add value to chemical risk assessment by reducing the assumptions regarding consumption rates, residue occurrence, and processing effects and by integrating exposures from different sources (diet, household use, environmental). However, the relationship between exposure and concentration in human matrices is unknown for most pesticides. Therefore, we conducted a pilot study to gain more insight into the qualitative and quantitative relationship between dietary intake of pesticides (external exposure) and urinary excretion (reflecting internal exposure). In this cross-sectional observational study, 35 healthy consumers aged 18-65 years from the region of Wageningen, Netherlands, collected an exact duplicate portion of their diets during 24 h. On the same day, they also collected all their urine. The duplicate diets were analyzed using target screening by GC- and LC-HRMS; each duplicate diet contained at least five, up to 21, pesticide residues. The 24 h urine samples were analyzed using LC-HRMS in a suspect screening workflow. Metabolites were tentatively detected in all 24 h urine samples, ranging from six metabolites corresponding to four pesticides up to 40 metabolites originating from 16 pesticides in a single urine sample. In total, 65 metabolites originating from 28 pesticides were tentatively detected. After prioritization and additional confirmation experiments, 28 metabolites originating from 10 pesticides were identified with confidence level 1 or 2b. Next, quantitative analysis was performed for a selection of pesticides in duplicate diets and their metabolites in 24 h urine to assess quantitative relationships. In the quantitative comparisons between duplicate diet and 24 h urine, it was found that some metabolites were already present in the duplicate diet, which may give an overestimation of exposure to the parent pesticide based on measurement of the metabolites in urine. Additionally, the quantitative comparisons suggest a background exposure through other exposure routes. We conclude that suspect screening of 24 h urine samples can disclose exposure to mixtures of pesticide on the same day in the general population. However, more research is needed to obtain quantitative relationships between dietary intake and exposure.

Development and validation of two analytical strategies for the determination of glucosides of acidic herbicides in cereals and oilseed matrices

The aim of the present research was the development and validation of a selective and reliable method for the indirect and direct determination of acidic herbicide glucosides. Enzymatic deconjugation was investigated as a mild alternative to harsh alkaline hydrolysis. Various enzymatic options for deconjugation were exploited. One out of nine tested specific enzymes proved to be practical and repeatable for different matrices and concentration ranges, leading to the complete deconjugation of the glucosides. The method was validated according to the SANTE/11312/2021 guideline for cereals and oilseeds and for a rice-based infant formula. Additionally, for four acidic herbicide glucosides available on the market, a quantitative method for direct determination of the intact glucosides was optimized and validated. In both methods, the average recoveries were within 70-120%. The limits of quantification (LOQ) achieved were 10 µg kg-1 and 2.5 µg kg-1 for the intact glucosides and the free acids in cereal and oilseeds. For the rice-based infant formula, the LOQ was 1 µg kg-1 (3 µg kg-1 for dichlorprop). To confirm its applicability, the deconjugation approach was tested for fifteen samples (cereals, oilseeds, and citrus) with incurred residues. Comparisons were made between the method without deconjugation, and two methods with deconjugation, the here proposed enzymatic deconjugation and the more commonly used alkaline hydrolysis. The inclusion of enzymatic deconjugation during sample preparation led to an increase up to 2.7-fold compared to analysis without deconjugation. Enzymatic deconjugation resulted in comparable results to alkaline hydrolysis for 13 out of 15 samples.

Occurrence of pesticide residues in indoor dust of farmworker households across Europe and Argentina

Pesticides are widely used as plant protection products (PPPs) in farming systems to preserve crops against pests, weeds, and fungal diseases. Indoor dust can act as a chemical repository revealing occurrence of pesticides in the indoor environment at the time of sampling and the (recent) past. This in turn provides information on the exposure of humans to pesticides in their homes. In the present study, part of the Horizon 2020 funded SPRINT project, the presence of 198 pesticide residues was assessed in 128 indoor dust samples from both conventional and organic farmworker households across Europe, and in Argentina. Mixtures of pesticide residues were found in all dust samples (25-121, min-max; 75, median). Concentrations varied in a wide range (<0.01 ng/g-206 μg/g), with glyphosate and its degradation product AMPA, permethrin, cypermethrin and piperonyl butoxide found in highest levels. Regarding the type of pesticides, insecticides showed significantly higher levels than herbicides and fungicides. Indoor dust samples related to organic farms showed a significantly lower number of residues, total and individual concentrations than those related to conventional farms. Some pesticides found in indoor dust were no longer approved ones (29 %), with acute/chronic hazards to human health (32 %) and with environmental toxicity (21 %).

Urinary pesticide mixture patterns and exposure determinants in the adult population from the Netherlands and Switzerland: Application of a suspect screening approach

INTRODUCTION

Non-occupational sources of pesticide exposure may include domestic pesticide usage, diet, occupational exposure of household members, and agricultural activities in the residential area. We conducted a study with the ambition to characterize pesticide mixture patterns in a sample of the adult population of the Netherlands and Switzerland, using a suspect screening approach and to identify related exposure determinants.

METHODS

A total of 105 and 295 adults participated in the Dutch and Swiss studies, respectively. First morning void urine samples were collected and analyzed in the same laboratory. Harmonized questionnaires about personal characteristics, pesticide-related activities, and diet were administered. Detection rates and co-occurrence patterns were calculated to explore internal pesticide exposure patterns. Censored linear and logistic regression models were constructed to investigate the association between exposure and domestic pesticide usage, consumption of homegrown and organic foods, household members' exposure, and distance to agricultural and forest areas.

RESULTS

From the 37 detected biomarkers, 3 (acetamiprid (-CH2), chlorpropham (4-HSA), and flonicamid (-C2HN)) were detected in ≥40% of samples. The most frequent combination of biomarkers (acetamiprid-flonicamid) was detected in 22 (5.5%) samples. Regression models revealed an inverse association between high organic vegetable and fruit consumption and exposure to acetamiprid, chlorpropham, propamocarb (+O), and pyrimethanil (+O + SO3). Within-individual correlations in repeated samples (summer/winter) from the Netherlands were low (≤0.3), and no seasonal differences in average exposures were observed in Switzerland.

CONCLUSION

High consumption of organic fruit and vegetables was associated with lower pesticide exposure. In the two countries, detection rates and co-occurrence were typically low, and within-person variability was high. Our study results provide an indication for target biomarkers to include in future studies aimed at quantifying urinary exposure levels in European adult populations.

Pesticide residues with hazard classifications relevant to non-target species including humans are omnipresent in the environment and farmer residences

Intensive and widespread use of pesticides raises serious environmental and human health concerns. The presence and levels of 209 pesticide residues (active substances and transformation products) in 625 environmental samples (201 soil, 193 crop, 20 outdoor air, 115 indoor dust, 58 surface water, and 38 sediment samples) have been studied. The samples were collected during the 2021 growing season, across 10 study sites, covering the main European crops, and conventional and organic farming systems. We profiled the pesticide residues found in the different matrices using existing hazard classifications towards non-target organisms and humans. Combining monitoring data and hazard information, we developed an indicator for the prioritization of pesticides, which can support policy decisions and sustainable pesticide use transitions. Eighty-six percent of the samples had at least one residue above the respective limit of detection. One hundred residues were found in soil, 112 in water, 99 in sediments, 78 in crops, 76 in outdoor air, and 197 in indoor dust. The number, levels, and profile of residues varied between farming systems. Our results show that non-approved compounds still represent a significant part of environmental cocktails and should be accounted for in monitoring programs and risk assessments. The hazard profiles analysis confirms the dominance of compounds of low-moderate hazard and underscores the high hazard of some approved compounds and recurring "no data available" situations. Overall, our results support the idea that risk should be assessed in a mixture context, taking environmentally relevant mixtures into consideration. We have uncovered uncertainties and data gaps that should be addressed, as well as the policy implications at the EU approval status level. Our newly introduced indicator can help identify research priority areas, and act as a reference for targeted scenarios set forth in the Farm to Fork pesticide reduction goals.

Current Advances, Research Needs and Gaps in Mycotoxins Biomonitoring under the HBM4EU-Lessons Learned and Future Trends

Mycotoxins are natural metabolites produced by fungi that contaminate food and feed worldwide. They can pose a threat to human and animal health, mainly causing chronic effects, e.g., immunotoxic and carcinogenic. Due to climate change, an increase in European population exposure to mycotoxins is expected to occur, raising public health concerns. This urges us to assess the current human exposure to mycotoxins in Europe to allow monitoring exposure and prevent future health impacts. The mycotoxins deoxynivalenol (DON) and fumonisin B1 (FB1) were considered as priority substances to be studied within the European Human Biomonitoring Initiative (HBM4EU) to generate knowledge on internal exposure and their potential health impacts. Several policy questions were addressed concerning hazard characterization, exposure and risk assessment. The present article presents the current advances attained under the HBM4EU, research needs and gaps. Overall, the knowledge on the European population risk from exposure to DON was improved by using new harmonised data and a newly derived reference value. In addition, mechanistic information on FB1 was, for the first time, organized into an adverse outcome pathway for a congenital anomaly. It is expected that this knowledge will support policy making and contribute to driving new Human Biomonitoring (HBM) studies on mycotoxin exposure in Europe.

Literature review and evaluation of biomarkers, matrices and analytical methods for chemicals selected in the research program Human Biomonitoring for the European Union (HBM4EU)

Humans are potentially exposed to a large amount of chemicals present in the environment and in the workplace. In the European Human Biomonitoring initiative (Human Biomonitoring for the European Union = HBM4EU), acrylamide, mycotoxins (aflatoxin B1, deoxynivalenol, fumonisin B1), diisocyanates (4,4'-methylenediphenyl diisocyanate, 2,4- and 2,6-toluene diisocyanate), and pyrethroids were included among the prioritized chemicals of concern for human health. For the present literature review, the analytical methods used in worldwide biomonitoring studies for these compounds were collected and presented in comprehensive tables, including the following parameter: determined biomarker, matrix, sample amount, work-up procedure, available laboratory quality assurance and quality assessment information, analytical techniques, and limit of detection. Based on the data presented in these tables, the most suitable methods were recommended. According to the paradigm of biomonitoring, the information about two different biomarkers of exposure was evaluated: a) internal dose = parent compounds and metabolites in urine and blood; and b) the biologically effective = dose measured as blood protein adducts. Urine was the preferred matrix used for deoxynivalenol, fumonisin B1, and pyrethroids (biomarkers of internal dose). Markers of the biological effective dose were determined as hemoglobin adducts for diisocyanates and acrylamide, and as serum-albumin-adducts of aflatoxin B1 and diisocyanates. The analyses and quantitation of the protein adducts in blood or the metabolites in urine were mostly performed with LC-MS/MS or GC-MS in the presence of isotope-labeled internal standards. This review also addresses the critical aspects of the application, use and selection of biomarkers. For future biomonitoring studies, a more comprehensive approach is discussed to broaden the selection of compounds.

A large scale multi-laboratory suspect screening of pesticide metabolites in human biomonitoring: From tentative annotations to verified occurrences

Within the Human Biomonitoring for Europe initiative (HBM4EU), a study to determine new biomarkers of exposure to pesticides and to assess exposure patterns was conducted. Human urine samples (N = 2,088) were collected from five European regions in two different seasons. The objective of the study was to identify pesticides and their metabolites in collected urine samples with a harmonized suspect screening approach based on liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) applied in five laboratories. A combined data processing workflow included comprehensive data reduction, correction of mass error and retention time (RT) drifts, isotopic pattern analysis, adduct and elemental composition annotation, finalized by a mining of the elemental compositions for possible annotations of pesticide metabolites. The obtained tentative annotations (n = 498) were used for acquiring representative data-dependent tandem mass spectra (MS2) and verified by spectral comparison to reference spectra generated from commercially available reference standards or produced through human liver S9 in vitro incubation experiments. 14 parent pesticides and 71 metabolites (including 16 glucuronide and 11 sulfate conjugates) were detected. Collectively these related to 46 unique pesticides. For the remaining tentative annotations either (i) no data-dependent MS2 spectra could be acquired, (ii) the spectral purity was too low for sufficient matching, or (iii) RTs indicated a wrong annotation, leaving potential for more pesticides and/or their metabolites being confirmed in further studies. Thus, the reported results are reflecting only a part of the possible pesticide exposure.

Developing human biomonitoring as a 21st century toolbox within the European exposure science strategy 2020-2030

Human biomonitoring (HBM) is a crucial approach for exposure assessment, as emphasised in the European Commission's Chemicals Strategy for Sustainability (CSS). HBM can help to improve chemical policies in five major key areas: (1) assessing internal and aggregate exposure in different target populations; 2) assessing exposure to chemicals across life stages; (3) assessing combined exposure to multiple chemicals (mixtures); (4) bridging regulatory silos on aggregate exposure; and (5) enhancing the effectiveness of risk management measures. In this strategy paper we propose a vision and a strategy for the use of HBM in chemical regulations and public health policy in Europe and beyond. We outline six strategic objectives and a roadmap to further strengthen HBM approaches and increase their implementation in the regulatory risk assessment of chemicals to enhance our understanding of exposure and health impacts, enabling timely and targeted policy interventions and risk management. These strategic objectives are: 1) further development of sampling strategies and sample preparation; 2) further development of chemical-analytical HBM methods; 3) improving harmonisation throughout the HBM research life cycle; 4) further development of quality control / quality assurance throughout the HBM research life cycle; 5) obtain sustained funding and reinforcement by legislation; and 6) extend target-specific communication with scientists, policymakers, citizens and other stakeholders. HBM approaches are essential in risk assessment to address scientific, regulatory and societal challenges. HBM requires full and strong support from the scientific and regulatory domain to reach its full potential in public and occupational health assessment and in regulatory decision-making.

A Tiered Approach for Assessing Individual and Combined Risk of Pyrethroids Using Human Biomonitoring Data

Pyrethroids are a major insecticide class, suitable for biomonitoring in humans. Due to similarities in structure and metabolic pathways, urinary metabolites are common to various active substances. A tiered approach is proposed for risk assessment. Tier I was a conservative screening for overall pyrethroid exposure, based on phenoxybenzoic acid metabolites. Subsequently, probabilistic approaches and more specific metabolites were used for refining the risk estimates. Exposure was based on 95th percentiles from HBM4EU aligned studies (2014-2021) covering children in Belgium, Cyprus, France, Israel, Slovenia, and The Netherlands and adults in France, Germany, Israel, and Switzerland. In all children populations, the 95th percentiles for 3-phenoxybenzoic acid (3-PBA) exceeded the screening value. The probabilistic refinement quantified the risk level of the most exposed population (Belgium) at 2% or between 1-0.1% depending on the assumptions. In the substance specific assessments, the 95th percentiles of urinary concentrations in the aligned studies were well below the respective human biomonitoring guidance values (HBM-GVs). Both information sets were combined for refining the combined risk. Overall, the HBM data suggest a low health concern, at population level, related to pyrethroid exposure for the populations covered by the studies, even though a potential risk for highly exposed children cannot be completely excluded. The proposed tiered approach, including a screening step and several refinement options, seems to be a promising tool of scientific and regulatory value in future.

European interlaboratory comparison investigations (ICI) and external quality assurance schemes (EQUAS) for the analysis of bisphenol A, S and F in human urine: Results from the HBM4EU project

The Human Biomonitoring for Europe initiative (HBM4EU) aims to study the exposure of citizens to chemicals and potentially associated health effects. One objective of this project has been to build a network of laboratories able to answer to the requirements of European human biomonitoring studies. Within the HBM4EU quality assurance and quality control scheme (QA/QC), a number of interlaboratory comparison investigations (ICIs) and external quality assurance schemes (EQUASs) were organized to ensure data consistency, comparability and reliability. Bisphenols are among the prioritized substance groups in HBM4EU, including bisphenol A (BPA), bisphenol S (BPS) and bisphenol F (BPF) in human urine. In four rounds of ICI/EQUAS, two target concentration levels were considered, related to around P25 and P95 of the typical exposure distribution observed in the European general population. Special attention was paid to the conjugated phase II metabolites known to be most dominant in samples of environmentally exposed individuals, through the analysis of both native samples and samples fortified with glucuronide forms. For the low level, the average percentage of satisfactory results across the four rounds was 83% for BPA, 71% for BPS and 62% for BPF. For the high level, the percentages of satisfactory results increased to 93% for BPA, 89% for BPS and 86% for BPF. 24 out of 32 participating laboratories (75%) were approved for the analyses of BPA in the HBM4EU project according to the defined criterion of Z-scores for both low and high concentration levels in at least two ICI/EQUAS rounds. For BPS and BPF, the number of qualified laboratories was 18 out of 27 (67%) and 13 out of 28 (46%), respectively. These results demonstrate a strong analytical capability for BPA and BPS in Europe, while improvements may be needed for BPF.

Pesticides in doormat and floor dust from homes close to treated fields: Spatio-temporal variance and determinants of occurrence and concentrations

Indoor dust has been postulated as an important matrix for residential pesticide exposure. However, there is a lack of information on presence, concentrations and determinants of multiple pesticides in dust in residential homes close to treated fields. Our objective was to characterize the spatial and temporal variance of pesticides in house dust, study the use of doormats and floors as proxies for pesticides in indoor dust and identify determinants of occurrence and concentrations. Homes within 250 m from selected bulb fields were invited to participate. Homes within 20 km from these fields but not having agricultural fields within 500 m were selected as controls. House dust was vacuumed in all homes from floors (VFD) and from newly placed clean doormats (DDM). Sampling was done during two periods, when pesticides are used and not-used. For determination of 46 prioritized pesticides, a multi-residue extraction method was used. Most statistical analyses are focused on the 12 and 14 pesticides that were detected in >40% of DDM and VFD samples, respectively. Mixed models were used to evaluate relationships between possible determinants and pesticides occurrence and concentrations in DDM and VFD. 17 pesticides were detected in more than 50% of the homes in both matrixes. Concentrations differed by about a factor five between use and non-use periods among homes within 250 m of fields and between these homes and controls. For 7 pesticides there was a moderate to strong correlation (Spearman rho 0.30-0.75) between concentrations in DDM and VFD. Distance to agricultural fields and air concentrations were among the most relevant predictors for occurrence and levels of a given pesticide in DDM. Concentrations in dust are overall higher during application periods and closer to fields (<250 m) than further away. The omnipresence of pesticides in dust lead to residents being exposed all year round.

Interlaboratory Comparison Investigations (ICIs) for human biomonitoring of chromium as part of the quality assurance programme under HBM4EU

BACKGROUND

The pan-European human biomonitoring initiative HBM4EU targets the harmonization of human biomonitoring (HBM) procedures and data for both environmental and occupational exposure, including chromium. The determination of chromium in urine (U-Cr), plasma (P-Cr) and whole blood (WB-Cr) is a common HBM application in employees occupationally exposed to chromium (VI) compounds.

METHODS

European laboratories which have registered as candidate laboratories for chromium analysis within HBM4EU were invited to participate in a quality assurance/qualitycontrol (QA/QC) programme comprising interlaboratory comparison investigations (ICI) for the parameters U-Cr, P-Cr and WB-Cr. Participating laboratories received two samples of different concentrations in each of four rounds and were asked to analyse the samples using their standard analytical procedure. The data were evaluated by the Z-score approach and were reported to the participants after each round.

RESULTS

The majority of the 29 participating laboratories obtained satisfactory results, although low limits of quantification were required to quantify chromium concentrations in some of the ICI materials. The robust relative standard deviation of the participants' results (study RSD_R) obtained from all ICI runs ranged from 6 to 16 % for U-Cr, 7-18 % for P-Cr and 4-47 % for WB-Cr. The application of both inductively coupled plasma mass spectrometry (ICP-MS) and electrothermal atomic absorption spectrometry (EAAS) appeared appropriate for the determination of chromium in urine, plasma and whole blood with regard to occupational exposure levels.

CONCLUSION

This QA/QC programme succeeded in establishing a network of laboratories with high analytical comparability and accuracy for the analysis of chromium across Europe.

Collection of human and environmental data on pesticide use in Europe and Argentina: Field study protocol for the SPRINT project

Current farm systems rely on the use of Plant Protection Products (PPP) to secure high productivity and control threats to the quality of the crops. However, PPP use may have considerable impacts on human health and the environment. A study protocol is presented aiming to determine the occurrence and levels of PPP residues in plants (crops), animals (livestock), humans and other non-target species (ecosystem representatives) for exposure modelling and impact assessment. To achieve this, we designed a cross-sectional study to compare conventional and organic farm systems across Europe. Environmental and biological samples were/are being/will be collected during the 2021 growing season, at 10 case study sites in Europe covering a range of climate zones and crops. An additional study site in Argentina will inform the impact of PPP use on growing soybean which is an important European protein-source in animal feed. We will study the impact of PPP mixtures using an integrated risk assessment methodology. The fate of PPP in environmental media (soil, water and air) and in the homes of farmers will be monitored. This will be complemented by biomonitoring to estimate PPP uptake by humans and farm animals (cow, goat, sheep and chicken), and by collection of samples from non-target species (earthworms, fish, aquatic and terrestrial macroinvertebrates, bats, and farm cats). We will use data on PPP residues in environmental and biological matrices to estimate exposures by modelling. These exposure estimates together with health and toxicity data will be used to predict the impact of PPP use on environment, plant, animal and human health. The outcome of this study will then be integrated with socio-economic information leading to an overall assessment used to identify transition pathways towards more sustainable plant protection and inform decision makers, practitioners and other stakeholders regarding farming practices and land use policy.

Interlaboratory comparison investigations (ICIs) and external quality assurance schemes (EQUASs) for flame retardant analysis in biological matrices: Results from the HBM4EU project

The European Human Biomonitoring Initiative (HBM4EU) is coordinating and advancing human biomonitoring (HBM). For this purpose, a network of laboratories delivering reliable analytical data on human exposure is fundamental. The analytical comparability and accuracy of laboratories analysing flame retardants (FRs) in serum and urine were investigated by a quality assurance/quality control (QA/QC) scheme comprising interlaboratory comparison investigations (ICIs) and external quality assurance schemes (EQUASs). This paper presents the evaluation process and discusses the results of four ICI/EQUAS rounds performed from 2018 to 2020 for the determination of ten halogenated flame retardants (HFRs) represented by three congeners of polybrominated diphenyl ethers (BDE-47, BDE-153 and BDE-209), two isomers of hexabromocyclododecane (α-HBCD and γ-HBCD), two dechloranes (anti-DP and syn-DP), tetrabromobisphenol A (TBBPA), decabromodiphenylethane (DBDPE), and 2,4,6-tribromophenol (2,4,6-TBP) in serum, and four metabolites of organophosphorus flame retardants (OPFRs) in urine, at two concentration levels. The number of satisfactory results reported by laboratories increased during the four rounds. In the case of HFRs, the scope of the participating laboratories varied substantially (from two to ten) and in most cases did not cover the entire target spectrum of chemicals. The highest participation rate was reached for BDE-47 and BDE-153. The majority of participants achieved more than 70% satisfactory results for these two compounds over all rounds. For other HFRs, the percentage of successful laboratories varied from 44 to 100%. The evaluation of TBBPA, DBDPE, and 2,4,6-TBP was not possible because the number of participating laboratories was too small. Only seven laboratories participated in the ICI/EQUAS scheme for OPFR metabolites and five of them were successful for at least two biomarkers. Nevertheless, the evaluation of laboratory performance using Z-scores in the first three rounds required an alternative approach compared to HFRs because of the small number of participants and the high variability of experts' results. The obtained results within the ICI/EQUAS programme showed a significant core network of comparable European laboratories for HBM of BDE-47, BDE-153, BDE-209, α-HBCD, γ-HBCD, anti-DP, and syn-DP. On the other hand, the data revealed a critically low analytical capacity in Europe for HBM of TBBPA, DBDPE, and 2,4,6-TBP as well as for the OPFR biomarkers.

Cocktails of pesticide residues in conventional and organic farming systems in Europe - Legacy of the past and turning point for the future

Considering that pesticides have been used in Europe for over 70 years, a system for monitoring pesticide residues in EU soils and their effects on soil health is long overdue. In an attempt to address this problem, we tested 340 EU agricultural topsoil samples for multiple pesticide residues. These samples originated from 4 representative EU case study sites (CSS), which covered 3 countries and four of the main EU crops: vegetable and orange production in Spain (S-V and S-O, respectively), grape production in Portugal (P-G), and potato production in the Netherlands (N-P). Soil samples were collected between 2015 and 2018 after harvest or before the start of the growing season, depending on the CSS. Conventional and organic farming results were compared in S-V, S-O and N-P. Soils from conventional farms presented mostly mixtures of pesticide residues, with a maximum of 16 residues/sample. Soils from organic farms had significantly fewer residues, with a maximum of 5 residues/sample. The residues with the highest frequency of detection and the highest content in soil were herbicides: glyphosate and its main metabolite AMPA (P-G, N-P, S-O), and pendimethalin (S-V). Total residue content in soil reached values of 0.8 mg kg^-1 for S-V, 2 mg kg^-1 for S-O and N-P, and 12 mg kg^-1 for P-G. Organic soils presented 70-90% lower residue concentrations than the corresponding conventional soils. There is a severe knowledge gap concerning the effects of the accumulated and complex mixtures of pesticide residues found in soil on soil biota and soil health. Safety benchmarks should be defined and introduced into (soil) legislation as soon as possible. Furthermore, the process of transitioning to organic farming should take into consideration the residue mixtures at the conversion time and their residence time in soil.

The European human biomonitoring platform - Design and implementation of a laboratory quality assurance/quality control (QA/QC) programme for selected priority chemicals

A fundamental objective of the human biomonitoring for Europe initiative (HBM4EU) is to progress toward comparable and robust exposure data for a wide variety of prioritized chemicals in human samples. A programme for Quality Assurance/Quality Control (QA/QC) was designed in HBM4EU with the purpose of creating a network of European laboratories providing comparable analytical data of high quality. Two approaches were chosen for two sets of prioritized chemicals with different timelines: (i) Scheme 1, where interested candidate laboratories participated in multiple rounds of proficiency tests (ii) Scheme 2, where selected expert laboratories participated in three rounds of interlaboratory comparison investigations. In both cases, the results were used to identify laboratories capable of generating consistent and comparable results for sample analysis in the frame of HBM4EU. In total, 84 laboratories from 26 countries were invited to participate in Scheme 1 that covered up to 73 biomarkers from Hexamoll® DINCH, phthalates, bisphenols, per- and polyfluoroalkyl substances, halogenated flame retardants (HFRs), organophosporous flame retardants (OPFRs), polycyclic aromatic hydrocarbons (PAH), cadmium, chromium and aromatic amines. 74 of the participants were successful for at least one biomarker in Scheme 1. Scheme 2 involved 22 biomarkers and successful results were obtained by 2 expert laboratories for arsenic, 5 for acrylamide, 4 for mycotoxins, 2 for pesticides and 2 for UV-filters in skin care products. The QA/QC programme allowed the identification of major difficulties and needs in HBM analysis as well of gaining insight in the analytical capacities of European laboratories. Furthermore, it is the first step towards the establishment of a sustainable European network of HBM laboratories.

Influence of different hydrophilic interaction liquid chromatography stationary phases on method performance for the determination of highly polar anionic pesticides in complex feed matrices

Hydrophilic interaction liquid chromatography is an alternative liquid chromatography mode for separation of polar compounds. In the recent years, this liquid chromatography mode has been recognized as an important solution for the analysis of compounds not amenable to reverse phase chromatography. In this work, we evaluated three different hydrophilic liquid chromatography stationary phases for the determination of 14 highly polar anionic molecules including pesticides such as glyphosate, glufosinate, ethephon and fosetyl, their main metabolites, and bromide, chlorate, and perchlorate. Several mobile phase compositions were evaluated combined with different gradients for the chromatographic run. The two columns that presented the best results were used to assess the performance for the determination of the 14 compounds in challenging highly complex feed materials. Very different matrix effects were observed for most of the compounds in each column, suggesting that different interactions can occur. Using isotopically labeled internal standards, acceptable quantitative performance and identification could be achieved down to 0.02 mg kg^-1 (the lowest level tested) for most compounds. While one column was found to be favorable in terms of scope (suited for all 14 compounds), the other one was more suited for quantification and identification at lower levels, however, not for all analytes tested.