Pesticide metabolite concentrations in Queensland pre-schoolers - Exposure trends related to age and sex using urinary biomarkers

A Comprehensive Review on Pesticide Residues in Human Urine

Numerous studies worldwide have evaluated pesticide residues detected in urine. This review serves as a contribution to this field by presenting an overview of scientific research studies published from 2001 to 2023, including details of study characteristics and research scope. Encompassing 72 papers, the review further delves into addressing key challenges in study design and method used such as sampling and analytical approaches, results adjustments, risk assessment, estimations, and results evaluation. The review explores urinary concentrations and detection frequency of metabolites of organophosphates and pyrethroids, as well as herbicides such as 2,4-D and glyphosate and their metabolites, across various studies. The association of the results with demographic and lifestyle variables were explored. While farmers generally have higher pesticide exposure, adopting organic farming practices can reduce the levels of pesticides detected in their urine. Residence close to agricultural areas has shown high exposure in some cases. Dietary exposure is especially high among people adopting a conventionally grown plant-rich dietary pattern. A higher detection level and frequency of detection are generally found in females and children compared to males. The implications of transitioning to organic and sustainable plant-rich diets for reducing pesticide exposure and potential health benefits for both adults and children require further investigation.

The relationship between pesticide exposures and primary headaches in adults: A cross-sectional study based on Rafsanjan cohort study

Objectives

Toxic substances can trigger headaches. The prevalence of pesticide use and headaches was high among the population of Rafsanjan.

Methods

A cross-sectional study was used to collect data from 9991 adults who participated via sampling people aged 35-70 years old of both genders from the Rafsanjan Cohort Study (RCS) in Iran. Demographic characteristics, habits, chronic primary headache (CPH), and episodic primary headache (EPH) were measured.

Results

The prevalence of CPH and EPH were 7.4 % and 29.9 % respectively. The multivariable model showed the odds of EPH increased significantly by the pesticide exposure on farm OR: 1.16 (1.02-1.34), in yard OR: 1.18 (1.01-1.39), duration of pesticide exposure in yard > median OR: 1.35 (1.06-1.73), at home OR: 1.31 (1.17-1.46), duration of pesticide exposure at home ≤ median OR: 1.24 (1.10-1.40) and > median OR: 1.38 (1.22-1.57). Also, pesticide preparation OR: 1.20 (1.03-1.39), duration of exposure in pesticide preparation ≤ median OR: 1.31 (1.09-1.57), and duration of exposure in managed spraying pesticide > median OR: 1.28 (1.04-1.57) increased odds of EPH. These results showed that the odds of CPH increased in participants using pesticides at home OR: 1.22 (1.02-1.48), duration of pesticide exposure at home > median OR: 1.37 (1.11-1.70), and duration of pesticide exposure in pesticide preparation > median OR: 0.47 (0.27-0.82). The odds of EPH increased with more pesticide exposures (18 %) and duration of pesticide exposure (25 %).

Conclusions

As evidenced by the obtained results, there is a relationship between pesticide exposure and headaches.

Frequency of urinary pesticides in children: a scoping review

Pesticides are any mix of ingredients and substances used to eliminate or control unwanted vegetable or animal species recognized as plagues. Its use has been discussed in research due to the scarcity of strong scientific evidence about its health effects. International literature is still insufficient to establish a global recommendation through public policy. This study aims to explore international evidence of the presence of pesticides in urine samples from children and their effects on health through a scoping review based on the methodology described by Arksey and O'Malley. The number of articles resulting from the keyword combination was 454, and a total of 93 manuscripts were included in the results and 22 were complementary. Keywords included in the search were: urinary, pesticide, children, and childhood. Children are exposed to pesticide residues through a fruit and vegetable intake environment and household insecticide use. Behavioral effects of neural damage, diabetes, obesity, and pulmonary function are health outcomes for children that are commonly studied. Gas and liquid chromatography-tandem mass spectrometry methods are used predominantly for metabolite-pesticide detection in urine samples. Dialkylphosphates (DAP) are common in organophosphate (OP) metabolite studies. First-morning spot samples are recommended to most accurately characterize OP dose in children. International evidence in PubMed supports that organic diets in children are successful interventions that decrease the urinary levels of pesticides. Several urinary pesticide studies were found throughout the world's population. However, there is a knowledge gap that is important to address (public policy), due to farming activities that are predominant in these territories.

Exposure to non-persistent pesticides and sexual maturation of Spanish adolescent males

BACKGROUND

Several non-persistent pesticides are endocrine disrupting chemicals and may impact on sexual maturation.

OBJECTIVE

To examine the association between urinary biomarkers of non-persistent pesticides and sexual maturation in adolescent males in the Environment and Childhood (INMA) Project.

METHODS

The metabolites of several pesticides were measured in spot urine samples collected from 201 boys aged 14-17 years, including: 3,5,6-trichloro-2-pyridinol (TCPy), metabolite of chlorpyrifos; 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy), metabolite of diazinon; malathion diacid (MDA), metabolite of malathion; diethyl thiophosphate (DETP) and diethyl dithiophosphate, non-specific metabolites of organophosphates; 3-phenoxybenzoic acid (3-PBA) and dimethyl cyclopropane carboxylic acid, metabolites of pyrethroids; 1-naphthol (1-NPL), metabolite of carbaryl; and ethylene thiourea (ETU), metabolite of dithiocarbamate fungicides. Sexual maturation was assessed using Tanner stages, self-reported Pubertal Development Scale, and testicular volume (TV). Multivariate logistic regression was employed to examine associations between urinary pesticide metabolites and the odds of being in Tanner stage 5 of genital development (G5) or pubic hair growth (PH5); stage ≥4 of overall pubertal development, gonadarche, and adrenarche; or having mature TV (≥25 mL).

RESULTS

DETP concentrations>75th percentile (P75) were associated with lower odds of being in stage G5 (OR = 0.27; 95% CI = 0.10-0.70), detectable TCPy with lower odds of gonadal stage≥4 (OR = 0.50; 95% CI = 0.26-0.96), and intermediate detectable MDA concentrations (<P75) with lower odds of adrenal stage≥4 (OR = 0.32; 95% CI = 0.11-0.94). Conversely, detectable concentrations of 1-NPL were associated with higher odds of adrenal stage≥4 (OR = 2.61; 95% CI = 1.30-5.24) but lower odds of mature TV (OR = 0.42; 95% CI = 0.19-0.90).

CONCLUSION

Exposure to certain pesticides may be associated with delayed sexual maturity in adolescent males.

Assessment of Preschool Children's Exposure Levels to Organophosphate and Pyrethroid Pesticide: A Human Biomonitoring Study in Two Turkish Provinces

Pesticides are products developed to prevent, destroy, repel or control certain forms of plant or animal life that are considered to be pests. However, now they are one of the critical risk factors threatening the environment, and they create a significant threat to the health of children. Organophosphate (OP) and pyrethroid (PYR) pesticides are widely used in Turkey as well as all over the world. The main focus of this presented study was to analyze the OP and PYR exposure levels in urine samples obtained from 3- to 6-year-old Turkish preschool children who live in the Ankara (n:132) and Mersin (n:54) provinces. In order to measure the concentrations of three nonspecific metabolites of PYR insecticides and four nonspecific and one specific metabolite of OPs, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses were performed. The nonspecific PYR metabolite 3-phenoxybenzoic acid (3-PBA) found in 87.1% of samples (n = 162) and the specific OP metabolite 3,5,6-trichloro-2-pyridinol (TCPY) found in 60.2% of samples (n = 112) were the most frequently detected metabolites in all urine samples. The mean concentrations of 3-PBA and TCPY were 0.38 ± 0.8 and 0.11 ± 0.43 ng/g creatinine, respectively. Although due to the large individual variation no statistically significant differences were found between 3-PBA (p = 0.9969) and TCPY (p = 0.6558) urine levels in the two provinces, significant exposure differences were determined both between provinces and within the province in terms of gender. Risk assessment strategies performed in light of our findings do not disclose any proof of a possible health problems related to analyzed pesticide exposure in Turkish children.

Contaminants of Emerging Concern (CECs) and Male Reproductive Health: Challenging the Future with a Double-Edged Sword

Approximately 9% of couples are infertile, with half of these cases relating to male factors. While many cases of male infertility are associated with genetic and lifestyle factors, approximately 30% of cases are still idiopathic. Contaminants of emerging concern (CECs) denote substances identified in the environment for the first time or detected at low concentrations during water quality analysis. Since CEC production and use have increased in recent decades, CECs are now ubiquitous in surface and groundwater. CECs are increasingly observed in human tissues, and parallel reports indicate that semen quality is continuously declining, supporting the notion that CECs may play a role in infertility. This narrative review focuses on several CECs (including pesticides and pharmaceuticals) detected in the nearshore marine environment of False Bay, Cape Town, South Africa, and deliberates their potential effects on male fertility and the offspring of exposed parents, as well as the use of spermatozoa in toxicological studies. Collective findings report that chronic in vivo exposure to pesticides, including atrazine, simazine, and chlorpyrifos, is likely to be detrimental to the reproduction of many organisms, as well as to sperm performance in vitro. Similarly, exposure to pharmaceuticals such as diclofenac and naproxen impairs sperm motility both in vivo and in vitro. These contaminants are also likely to play a key role in health and disease in offspring sired by parents exposed to CECs. On the other side of the double-edged sword, we propose that due to its sensitivity to environmental conditions, spermatozoa could be used as a bioindicator in eco- and repro-toxicology studies.

Detections of organophosphate and pyrethroid insecticide metabolites in urine and sweat obtained from women during infrared sauna and exercise: A pilot crossover study

Synthetic pesticides such as organophosphates and pyrethroids are commonly used worldwide yet the metabolic and long-term human health effects of these environmental exposures are unclear. Urinary detections of metabolites involving both classes of insecticides have been documented in various global populations. However, reports documenting similar detections in human sweat are sparse. In this study, the concentrations of four insecticide metabolites were measured using liquid chromatography coupled with tandem mass spectrometry in repeated sweat and urine collections (n = 85) from 10 women undergoing three interventions (control, infrared sauna and indoor bicycling) within a single-blinded randomised crossover trial. The Friedman test with post-hoc two-way analysis of variance, the related-samples Wilcoxon signed rank test and the Spearman's rank-order correlation test were used to analyse the results. Organophosphate metabolites were detected in 84.6% (22/26) and pyrethroids in 26.9% (7/26) of the collected sweat samples (pooled per individual, per intervention). Urinary concentrations of three of the four metabolites marginally increased after infrared sauna bathing: 3,5,6-trichloro-2-pyridinol (z = 2.395, p = 0.017); 3-phenoxybenzoic acid (z = 2.599, p = 0.009); and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (z = 2.090, p = 0.037). Urinary 3-phenoxybenzoic acid also increased after exercise (z = 2.073, p = 0.038) and demonstrated the most temporal variability (days to weeks) of any of the urinary metabolites. Definitive sweat/urine correlations were not demonstrated. These results indicate metabolites from organophosphate and pyrethroid pesticides can be detected in human sweat and this raises intriguing questions about perspiration and its role in the metabolism and excretion of synthetic pesticides.

How pesticides affect neonates? - Exposure, health implications and determination of metabolites

This review covers key information related to the effects of pesticides on fetal and child health. All humans are exposed to environmental toxicants, however child's health, due to their high vulnerability, should be of special concern. They are continuously exposed to environmental xenobiotics including a wide variety of pesticides, and other pollutants. These compounds can enter the child's body through various routes, both during fetal life, in the first days of life with breast milk, as well as during environmental exposure in later years of life. Consequently, in the body, some of them are metabolized and excreted with urine or faces, while others accumulate in tissues causing toxic effects. This review will provide information on the types of pesticides, their pathways of uptake and metabolism in children's bodies. Determination of the impact of them on children's organism performance is possible through effective identification of these compounds and their metabolites in children's tissues and biofluids. Therefore, the main procedures for the determination of pesticides are reviewed and future trends in this field are indicated. We believe that this comprehensive review can be a good starting place for the future readers interested in the impact of environmental xenobiotics on the health of children as well as the aspects relates with the analytical methods that can be used for analysis and monitoring of these pollutants in children's tissues and biofluids.

Child and family factors associated with positive outcomes among youth born extremely preterm

BACKGROUND

To analyze the relationship of child behavioral and communication disorders, and adverse family events, to later-in-life child health and cognitive function among youth born extremely preterm.

METHODS

The study participants were 694 children enrolled in the Extremely Low Gestational Age Newborn Study. At ages 2 and 10, we assessed internalizing and externalizing behaviors, and at age 10, we assessed adverse life events within the family. Associations were evaluated between these child and family factors and positive child health at age 10 years, and global health and cognitive function at age 15 years.

RESULTS

Lower T-scores for internalizing or externalizing behaviors at age 2 were associated with more positive health at age 10. The absence of internalizing behaviors at age 10 was associated with better global child health and better cognitive function at age 15. The absence of communication deficits at age 10 was associated with better cognitive function at age 15. The absence of parent job loss was associated with better global child health at age 15.

CONCLUSION

Among individuals born extremely preterm, child health and cognitive outcomes might be improved by timely interventions to address child behavioral symptoms and the impact of adverse life events in the family.

IMPACT

The absence of child behavioral and communication disorders, and adverse family events, were associated with more positive health, higher global health, and better cognitive function among youth born extremely preterm. Interventions to address behavioral disorders in early childhood, and to reduce the impact of adverse life events on the family, might promote improved health and developmental outcomes for adolescents born extremely preterm.

Childhood exposure to non-persistent pesticides and pubertal development in Spanish girls and boys: Evidence from the INMA (Environment and Childhood) cohort

This study assessed cross-sectional associations between urinary metabolites of non-persistent pesticides and pubertal development in boys and girls from urban and rural areas in Spain and examined effect modification by body mass index (BMI). Four metabolites of insecticides (TCPy, metabolite of chlorpyrifos; IMPy, metabolite of diazinon; DETP, non-specific metabolite of organophosphates; 3-PBA, metabolite of pyrethroids) and the metabolite of ethylene-bis-dithiocarbamate fungicides (ETU) were quantified in urine collected in 2010-2016 from 7 to 11-year-old children (606 girls, 933 boys) participating in the INMA Project. Pubertal development was ascertained by Tanner stages and/or parent-reported Pubertal Development Scale (PDS). Associations between pesticide metabolites and odds of being in stage 2+ for breast development (girls), genital development (boys), pubic hair growth (girls and boys), and/or overall puberty onset, gonadarche, and adrenarche (PDS for girls and boys) were examined by mixed-effect logistic regression. Effect modification by BMI was explored by interaction terms and stratified analysis. In girls, DETP and ETU concentrations>75th percentile (P75) were associated with higher odds of overall puberty development (OR [95%CI] = 1.86 [1.07-3.24] and 1.71 [1.03-2.83], respectively, for > P75 vs. undetected concentrations), while ETU > P75 was also associated with higher odds of breast development (OR [95%CI] = 5.55 [2.83-12.91]), particularly in girls with underweight/normal weight (OR [95%CI] = 10.08 [2.62-38.76]). In boys, detection of TCPy (40%) and 3-PBA (34%) was associated with higher odds of genital development (OR [95%CI] = 1.97 [1.08-3.57] and 2.08 [1.15-3.81], respectively), and the association with 3-PBA was observed in boys with overweight/obesity alone. In addition, ETU > P75 was associated with higher odds of genital development in boys with underweight/normal weight (OR [95%CI] = 2.89 [1.08-7.74]) but higher DETP with lower odds of puberty in boys with overweight/obesity (OR [95%CI] = 0.94 [0.89-0.99] per log-unit increase in concentration). Results suggest an association of childhood exposure to ETU and certain insecticides with earlier puberty in girls and boys that may be modified by child BMI.

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.

Occupational and residential exposures to organophosphate and pyrethroid pesticides in a rural setting

Organophosphate (OP) and pyrethroid pesticides (PYR) are extensively used in agriculture, resulting in higher exposures among farmworkers. The present study reports the occurrence of 8 urinary OP and PYR metabolites in a sample of farmworkers and residents from Sucs (n = 87), a rural township in North West Catalonia (Spain). The aim of the present study was to examine differences in urinary pesticide metabolite concentrations between occupationally-exposed (farmworkers; n = 45) and environmentally-exposed subjects (n = 42) and to assess the relationship between pesticide's exposures and occupational activities in a real-case scenario. Six OP and two PYR metabolites have been investigated, urine samples were extracted using SPE extraction and analyzed by UPLC-MS/MS. Three OP metabolites were commonly detectable in urine, namely TCPY (metabolite of chlorpyrifos), PNP (parathion) and DEAMPY (pirimiphos). Regarding pyrethroids, the two analyzed metabolites, 3-PBA and 4F-3-PBA, were detected in a high proportion of urine samples. Differences in concentrations between both groups were statistically significant for TCPY and 4F-3-PBA (Mann-Whitney U Test for independent groups, p < 0.05). In the case of TCPY, the concentrations were higher among the farmworkers, which is consistent with their occupational activity. The small differences found in DEAMPY, PNP, 3-PBA or even the significant higher concentrations of 4F-3-PBA among rural population suggest a general exposure to these compounds, even in those who do not carry an occupational activity. Specific personal protective equipment (PPE) among farmworkers, such as the use of gloves and mask during mixing, showed a decrease in the exposure levels, although the differences were not statistically significant. However, a positive association was found between the use of a cap during mixing (for PNP and 3-PBA) and during application (only for 3-PBA). However, this piece of cloth is mainly used for sun protection, and when not cleaned after the handling of pesticides, it might represent a continuous source of exposure through dermal contact. Farmworkers using tractors with cabin had statistically significant lower concentrations of DEAMPY than those using a tractor without cabin. The previous results suggest that occupational protections should be encouraged among farmworkers and other potential workers handling with pesticides.

Simultaneous determination of 16 urinary metabolites of organophosphate flame retardants and organophosphate pesticides by solid phase extraction and ultra performance liquid chromatography coupled to tandem mass spectrometry

Organophosphate flame retardants (OPFRs) and organophosphate pesticides (OPPs), pertaining to organophosphate esters, are ubiquitous in environment and have been verified to pose noticeable risks to human health. To evaluate human exposures to OPFRs and OPPs, a fast and sensitive approach based on a solid phase extraction (SPE) followed by the ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) detection has been developed for the simultaneous analysis of multiple organophosphorus metabolites in urine. The method allows the identification and quantification of ten metabolites of the most common OPFRs and all six dialkylphosphates (DAPs) of OPPs concerning the population exposure characteristics. The method provided good linearities (R² = 0.998-0.999), satisfactory method detection limits (MDLs) (0.030-1.129 ng/mL) and only needed a small volume (200 μL) of urine. Recovery rates ranged 73.4-127.1% at three spiking levels (2, 10 and 25 ng/mL urine), with both intra- and inter-day precision less than 14%. The good correlations for DAPs in a cross-validation test with a previous gas chromatography-mass spectrometry (GC-MS) method and a good inter-laboratory agreement for several OPFR metabolites in a standard reference material (SRM 3673) re-enforced the precision and validity of our method. Finally, the established method was successfully applied to analyze 16 organophosphorus metabolites in 35 Chinese children's urine samples. Overall, by validating the method's sensitivity, accuracy, precision, reproducibility, etc., data reliability and robustness were ensured; and the satisfactory pilot application on real urine samples demonstrated feasibility and acceptability of this method for being implemented in large population-based studies.

Pesticide exposure in New Zealand school-aged children: Urinary concentrations of biomarkers and assessment of determinants

This study aimed to assess pesticide exposure and its determinants in children aged 5-14 years. Urine samples (n = 953) were collected from 501 participating children living in urban areas (participant n = 300), rural areas but not on a farm (n = 76), and living on a farm (n = 125). The majority provided two samples, one in the high and one in the low spraying season. Information on diet, lifestyle, and demographic factors was collected by questionnaire. Urine was analysed for 20 pesticide biomarkers by GC-MS/MS and LC-MS/MS. Nine analytes were detected in > 80% of samples, including six organophosphate insecticide metabolites (DMP, DMTP, DEP, DETP, TCPy, PNP), two pyrethroid insecticide metabolites (3-PBA, trans-DCCA), and one herbicide (2,4-D). The highest concentration was measured for TCPy (median 13 μg/g creatinine), a metabolite of chlorpyrifos and triclopyr, followed by DMP (11 μg/g) and DMTP (3.7 μg/g). Urine metabolite levels were generally similar or low compared to those reported for other countries, while relatively high for TCPy and pyrethroid metabolites. Living on a farm was associated with higher TCPy levels during the high spray season. Living in rural areas, dog ownership and in-home pest control were associated with higher levels of pyrethroid metabolites. Urinary concentrations of several pesticide metabolites were higher during the low spraying season, possibly due to consumption of imported fruits and vegetables. Organic fruit consumption was not associated with lower urine concentrations, but consumption of organic food other than fruit or vegetables was associated with lower concentrations of TCPy in the high spray season. In conclusion, compared to other countries such as the U.S., New Zealand children had relatively high exposures to chlorpyrifos/triclopyr and pyrethroids. Factors associated with exposure included age, season, area of residence, diet, in-home pest control, and pets.

Exposure to non-persistent pesticides in the Spanish population using biomonitoring: A review

Although Spain does not have a regular national human biomonitoring program yet, different research groups are active in evaluating the exposure of children and adults to chemicals. In the last seven years, several studies in Spain have evaluated the internal exposure of the population to currently used pesticides. The present review analyzes the scope of these studies, the employed analytical methods and the main results of the exposure and risk, mainly for children and mothers. The frequency of exposure to biomarkers of exposure to organophosphate pesticides is high. Some non-specific dialkyl phosphate metabolites (DAPs), such as the diethyl phosphate (DEP), present Detection Frequencies (DFs) in the range of 65-92% in various studies. Also, the specific biomarker of the chlorpyrifos (3,5,6-trichloro-2-pyridinol, TCPy), achieves Detection Frequencies between 74% and 100% in many studies. For pyrethroids, the metabolite 3-phenoxybenzoic acid (PBA) is present, in general, in more than the 65% of the studied samples. Highly polar herbicides were only assessed in one study and both glyphosate and its metabolite aminomethylphosphonic acid showed Detection Frequencies around 60%. However, putting the biomonitoring data in a risk assessment context, the mean Hazard Quotient (HQ), used as a metric for the individual risk, ranges from 0.0006 (glyphosate) to 0.93 in farm workers (parathion), which means that is unlike that the exposure poses a health concern (HQ < 1).

Wastewater-based epidemiology as a novel tool to evaluate human exposure to pesticides: Triazines and organophosphates as case studies

Production and application of pesticides have risen remarkably in the last few decades. Even if they provide many benefits, they can be hazardous for humans and ecosystems when they are not used cautiously. Human exposure to pesticides is well documented, but new approaches are needed to boost the available information. This work proposes a new application of wastewater-based epidemiology (WBE) to assess the exposure of the general population to organophosphate and triazine pesticides (pyrethroid pesticides have already been validated). Several human urinary metabolites tested as WBE biomarkers, were suitable. Untreated wastewater samples from different European countries were analyzed by liquid chromatography-tandem mass spectrometry. Biomarker concentrations were converted to mass loads and used to back-calculate the local population's exposure to the parent pesticides, using specific correction factors developed in this study. Exposure to organophosphates and pyrethroids showed spatial and seasonal variations. Finally, pesticide exposure was estimated in twenty cities of ten European countries and compared with the acceptable daily intake, concluding that some populations might face health risks. The study confirms WBE as a suitable approach for assessing the average community exposure to pesticides and is a valuable complementary biomonitoring tool. WBE can provide valuable data for public health.

Is there an optimal sampling time and number of samples for assessing exposure to fast elimination endocrine disruptors with urinary biomarkers?

In studies investigating the effects of endocrine disruptors (ED) such as phthalates, bisphenols and some pesticides on human health, exposure is usually characterized with urinary metabolites. The variability of biomarkers concentration, due to rapid elimination from the body combined with frequent exposure is however pointed out as a major limitation to exposure assessment. This study was conducted to assess variability of urinary metabolites of ED, and to investigate how sampling time and number of samples analyzed impacts exposure assessment. Urine samples were collected over 6 months from 16 volunteers according to a random sampling design, and analyzed for 16 phthalate metabolites, 9 pesticide metabolites and 4 bisphenols. The amount of biomarkers excreted in urine at different times of the day were compared. In parallel, 2 algorithms were developed to investigate the effect of the number of urine samples analyzed per subject on exposure assessment reliability. In the 805 urine samples collected from the participants, all the biomarkers tested were detected, and 18 were present in >90% of the samples. Biomarkers variability was highlighted by the low intraclass correlation coefficients (ICC) ranging from 0.09 to 0.51. Comparing the amount of biomarkers excreted in urine at different time did not allow to identify a preferred moment for urine collection between first day urine, morning, afternoon and evening. Algorithms demonstrated that between 10 (for monobenzyl (MBzP) phthalate) and 31 (for bisphenol S) samples were necessary to correctly classify 87.5% of the subjects into quartiles according to their level of exposure. The results illustrate the high variability of urinary biomarkers of ED over time and the impossibility to reliably classify subjects based on a single urine sample (or a limited number). Results showed that classifying individuals based on urinary biomarkers requires several samples per subject, and this number is highly different for different biomarkers.

Exposure and cumulative risk assessment to non-persistent pesticides in Spanish children using biomonitoring

The main objective of the present research is to evaluate the exposure to pesticides in children (n = 568) from the Valencian Region (Spain). Six non-specific and 20 specific metabolites of organophosphate pesticides (OPs), herbicides (Herb), and pyrethroids (Pyr) were analyzed in urine samples. The biomarkers with the highest detection frequencies (>70%) were diethyl phosphate, p-nitrophenol, 3-phenoxybenzoic acid, and 3,5,6-trichloro-2-pyridinol, whose geometric mean concentrations (ng·ml-n1) were 1.53, 1.03, 1.51 and 1.19, respectively. Robust regression models showed that the province of residence and the recent consumption of vegetables, legumes and cereals were some of the most important predictors of pesticide exposure. Pesticide risk assessment is estimated using two different strategies: one based on the pesticides' mode of action (MoA); and the other based on cumulative assessment groups (CAGs), proposed by EFSA. The estimated daily intakes (EDIs) ranged from 0.08 (chlorpyrifos) to 1.62 μg·kg bw-1 (λ-cyhalothrin). The MoA approach resulted in hazard quotients ranging from 0.01 (chlorpyrifos) to 0.65 (λ-cyhalothrin), and a hazard index for OPs lower than 1. Similarly, the risk assessment based on CAGs led to total margins of exposure (MOETs) far from 100. In conclusion, both risk assessment strategies does not reveal any evidence of a potential health risk due to pesticide exposure in Spanish children.

Mother/child organophosphate and pyrethroid distributions

The present study reports one of the few cases in which organophosphate (OP) and pyrethroid (PYR) pesticide human exposure is evaluated in family contexts by the analysis of mother/child pair samples. Urinary concentrations of 6 organic metabolites of organophosphates and 2 pyrethroids were measured in mothers and their 7-to 8-year-old children (n = 168) in a general population from the central area of Slovenia. The results were adjusted for specific gravity and creatinine. The most abundant OP metabolite in children was 4-nitrophenol (PNP) (median 0.7 ng/ml) and in mothers (0.45 ng/ml), representing parathion exposure. 3-Phenoxibenzoic acid (3-PBA) (0.26 ng/ml), the general metabolite of pyrethroids, and 3,5,6-trichloro-2-pyridinol (TCPY) (0.16 ng/ml; chlorpyriphos) were the second most abundant compounds in children and mothers, respectively. The geometric mean specific gravity adjusted concentrations of OPs and PYRs were statistically significantly higher in children than in their mothers (between 3% and 24% higher), with the exception of TCPY (26% lower). All OP and PYR metabolites found in higher concentration in children showed significant positive correlations with the metabolite concentrations found in the mothers (p < 0.05 and 0.01), involving the fact that higher maternal concentrations were associated with higher children levels. These differential mother-children distributions and significant correlations were observed for the 2 types of pesticides studied, OPs and PYRs, which have different chemical properties. This agreement is consistent with the incorporation of the pesticides because of the general activities developed in the family context, instead of pesticide-dependent specific inputs. Comparison of the estimated daily intakes with the acceptable daily intakes of all detected metabolites revealed no significant risk of adverse health effects from exposure to these pesticides.

Development of a questionnaire-based insecticide exposure assessment method and comparison with urinary insecticide biomarkers in young Australian children

Environmental and behavioural factors assessed via an online questionnaire were compared to insecticide metabolite concentrations in urine collected from 61 children from South East Queensland, Australia. Metabolite concentrations (μg/L urine) were transformed using the natural logarithm prior to regression analysis and adjusted for age and creatinine. A significant dietary association was reported for vegetable intake and 3-phenoxybenzoic acid (3-PBA) (β: 1.47 for top quartile of intake versus bottom quartile of intake 95% CI: 0.36, 2.57). Intake of vegetables and fruit were also positively associated with sum non-specific organophosphate metabolites (ƩnsOP). ƩnsOP concentrations were lower when fruits and vegetables were always or almost always washed prior to cooking or eating (β: -0.69 95% CI: -1.25, -0.12). In multivariable modelling 3-PBA concentrations were also associated with hand-washing frequency (β: 1.69 95% CI: 0.76, 2.61 for <1 day versus > 3 day), presence of a dog in the home (β: 0.73 95% CI: 0.07, 1.38), frequency of pest-spray use in the summer months (β: 0.88 95% CI: 0.22, 1.54 weekly versus less than weekly) and season (β: 0.88 95% CI: 0.32, 1.44 for spring/summer versus winter/autumn). This is the first study in Australia to report dietary, behavioural and environmental factors associated with biomarkers of insecticide exposure in young children.

Insight Into Microbial Applications for the Biodegradation of Pyrethroid Insecticides

Pyrethroids are broad-spectrum insecticides and presence of chiral carbon differentiates among various forms of pyrethroids. Microbial approaches have emerged as a popular solution to counter pyrethroid toxicity to marine life and mammals. Bacterial and fungal strains can effectively degrade pyrethroids into non-toxic compounds. Different strains of bacteria and fungi such as Bacillus spp., Raoultella ornithinolytica, Psudomonas flourescens, Brevibacterium sp., Acinetobactor sp., Aspergillus sp., Candida sp., Trichoderma sp., and Candia spp., are used for the biodegradation of pyrethroids. Hydrolysis of ester bond by enzyme esterase/carboxyl esterase is the initial step in pyrethroid biodegradation. Esterase is found in bacteria, fungi, insect and mammalian liver microsome cells that indicates its hydrolysis ability in living cells. Biodegradation pattern and detected metabolites reveal microbial consumption of pyrethroids as carbon and nitrogen source. In this review, we aim to explore pyrethroid degrading strains, enzymes and metabolites produced by microbial strains. This review paper covers in-depth knowledge of pyrethroids and recommends possible solutions to minimize their environmental toxicity.