Pyrethroids in house dust from the homes of farm worker families in the MICASA study

Indoor pesticide exposure is a growing concern, particularly for pyrethroids, a commonly used class of pesticides. Pyrethroid concentrations may be especially high in homes of immigrant farm worker families, who often live in close proximity to agricultural fields and are faced with poor housing conditions, potentially causing high pest infestation and pesticide use. We investigate levels of pyrethroids in the house dust of farm worker family homes in a study of mothers and children living in Mendota, CA, within the population-based Mexican Immigration to California: Agricultural Safety and Acculturation (MICASA) Study. We present pesticide use data and levels of pyrethroid pesticides in indoor dust collected in 2009 as measured by questionnaires and a GC/MS analysis of the pyrethroids cis- and trans-permethrin, cypermethrin, deltamethrin, esfenvalerate and resmethrin in single dust samples collected from 55 households. Cis- and trans-permethrin had the highest detection frequencies at 67%, with median concentrations of 244 and 172 ng/g dust, respectively. Cypermethrin was detected in 52% of the homes and had a median concentration of 186 ng/g dust. Esfenvalerate, resmethrin and deltamethrin were detected in less than half the samples. We compared the pyrethroid concentrations found in our study to other studies looking at both rural and urban homes and daycares. Lower detection frequencies and/or lower median concentrations of cis- and trans-permethrin and cypermethrin were observed in our study as compared to those studies. However, deltamethrin, esfenvalerate and resmethrin were detected more frequently in the house dust from our study than in the other studies. Because households whose children had higher urinary pyrethroid metabolite levels were more likely to be analyzed in this study, a positive bias in our estimates of household pyrethroid levels may be expected. A positive association was observed with reported outdoor pesticide use and cypermethrin levels found in the indoor dust samples (r_s = 0.28, p = 0.0450). There was also a positive association seen with summed pyrethroid levels in house dust and the results of a pesticide inventory conducted by field staff (r_s = 0.32, p = 0.018), a potentially useful predictor of pesticide exposure in farm worker family homes. Further research is warranted to fully investigate the utility of such a measure.     

Strategic environmental noise mapping: Methodological issues concerning the implementation of the EU Environmental Noise Directive and their policy implications

This paper explores methodological issues and policy implications concerning the implementation of the EU Environmental Noise Directive (END) across Member States. Methodologically, the paper focuses on two key thematic issues relevant to the Directive: (1) calculation methods and (2) mapping methods. For (1), the paper focuses, in particular, on how differing calculation methods influence noise prediction results as well as the value of the EU noise indicator L_den and its associated implications for comparability of noise data across EU states. With regard to (2), emphasis is placed on identifying the issues affecting strategic noise mapping, estimating population exposure, noise action planning and dissemination of noise mapping results to the general public. The implication of these issues for future environmental noise policy is also examined.     

Functional paraoxonase 1 variants modify the risk of Parkinson's disease due to organophosphate exposure

BackgroundWe previously demonstrated that carriers of the “slower metabolizer” MM genotype of paraoxonase (PON1) who were also exposed to ambient organophosphate (OP) pesticides at their residences were at increased risk of developing Parkinson's disease (PD). Here, with a larger sample size, we extend our previous investigation to consider additional sources of ambient exposure and examined two additional functional PON1 variants.MethodsFrom 2001 to 2011, we enrolled incident cases of idiopathic PD and population controls living in central California. We genotyped three well-known functional PON1 SNPs: two exonic polymorphisms (PON1_L55M and PON1_Q192R) and the promoter region variant (PON1_C-108T). Ambient exposures to diazinon, chlorpyrifos, and parathion at residential and workplace addresses were assessed using a validated geographic information system-based model incorporating records of agricultural pesticide applications in California.ResultsThe odds ratio (OR) for Caucasians exposed to OPs at either residential or workplace addresses varied by PON1 genotype; for exposed carriers of the “faster” metabolizer genotypes, ML or LL, we estimated lower odds ratios (range, 1.20–1.39) than for exposed carriers of the “slower” metabolizer genotype MM (range, 1.78–2.45) relative to unexposed carriers of the faster genotypes. We observed similarly increased ORs for exposure across PON1_Q192R genotypes, but no differences across PON1_C-108T genotypes. The largest ORs were estimated for exposed carriers of both PON1_192QQ and PON1_55MM (OR range, 2.84–3.57).ConclusionsSeveral functional PON1 variants may act together to modify PD risk for ambient OP exposures. While either PON1_L55M or PON1_Q192R may be sufficient to identify increased susceptibility, carriers of both slow metabolizer variants seem most susceptible to OP exposures.     

Association of persistent organic pollutants and non-persistent pesticides with diabetes and diabetes-related health outcomes in Asia: A systematic review

BackgroundOver half of the people with diabetes in the world live in Asia. Emerging scientific evidence suggests that diabetes is associated with environmental pollutants, exposures that are also abundant in Asia.ObjectiveTo systematically review the literature concerning the association of persistent organic pollutants (POPs) and non-persistent pesticides with diabetes and diabetes-related health outcomes in Asia.MethodsPubMed and Embase were searched to identify studies published up to November 2014. A secondary reference review of all extracted articles and the National Toxicology Program Workshop on the association of POPs with diabetes was also conducted. A total of 19 articles met the inclusion criteria and were evaluated in this review.ResultsTo date, the evidence relating POPs and non-persistent pesticides with diabetes in Asian populations is equivocal. Positive associations were reported between serum concentrations of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and several organochlorine pesticides (DDT, DDE, oxychlordane, trans-nonachlor, hexachlorobenzene, hexachlorocyclohexane) with diabetes. PCDD/Fs were also associated with blood glucose and insulin resistance, but not beta-cell function. There were substantial limitations of the literature including: most studies were cross-sectional, few studies addressed selection bias and confounding, and most effect estimates had exceptionally wide confidence intervals. Few studies evaluated the effects of organophosphates.ConclusionsWell-conducted research is urgently needed on these pervasive exposures to inform policies to mitigate the diabetes epidemic in Asia.     

Prenatal exposure to multiple pesticides is associated with auditory brainstem response at 9 months in a cohort study of Chinese infants

BackgroundPesticides are associated with poorer neurodevelopmental outcomes, but little is known about the effects on sensory functioning.MethodsAuditory brainstem response (ABR) and pesticide data were available for 27 healthy, full-term 9-month-old infants participating in a larger study of early iron deficiency and neurodevelopment. Cord blood was analyzed by gas chromatography–mass spectrometry for levels of 20 common pesticides. The ABR forward-masking condition consisted of a click stimulus (masker) delivered via ear canal transducers followed by an identical stimulus delayed by 8, 16, or 64 milliseconds (ms). ABR peak latencies were evaluated as a function of masker-stimulus time interval. Shorter wave latencies reflect faster neural conduction, more mature auditory pathways, and greater degree of myelination. Linear regression models were used to evaluate associations between total number of pesticides detected and ABR outcomes. We considered an additive or synergistic effect of poor iron status by stratifying our analysis by newborn ferritin (based on median split).ResultsInfants in the sample were highly exposed to pesticides; a mean of 4.1 pesticides were detected (range 0–9). ABR Wave V latency and central conduction time (CCT) were associated with the number of pesticides detected in cord blood for the 64 ms and non-masker conditions. A similar pattern seen for CCT from the 8 ms and 16 ms conditions, although statistical significance was not reached. Increased pesticide exposure was associated with longer latency. The relation between number of pesticides detected in cord blood and CCT depended on the infant's cord blood ferritin level. Specifically, the relation was present in the lower cord blood ferritin group but not the higher cord blood ferritin group.ConclusionsABR processing was slower in infants with greater prenatal pesticide exposure, indicating impaired neuromaturation. Infants with lower cord blood ferritin appeared to be more sensitive to the effects of prenatal pesticide exposure on ABR latency delay, suggesting an additive or multiplicative effect.     

Change in the quantity and acute toxicity of pesticides sold in South African crop sectors, 1994–1999

BackgroundSouth African pesticide market sales data, for two years, 1994 and 1999, were audited to identify change in total and per hectare mass sold and acute toxicity indicator (ATI) (kg sold/rat oral LD50) in the grape, pome, stone fruit, potato and wheat sectors.ResultsTotal pesticide sales (62%), amount per hectare (42%) and number of active ingredients (23%) increased in 1999 compared to 1994 with the grape fruit sector, the most significant contributor over the two years. Total (14%) and per hectare ATI (19%) decreased in 1999, but not substantially with the potato sector the most significant contributor.ConclusionsToxic pesticides were still used in 1999 which highlights a need to develop alternative agricultural and non-chemical pest control methods that reduce usage of pesticides.     

Farm residence and reproductive health among boys in rural South Africa

BackgroundFew studies have investigated reproductive health effects of contemporary agricultural pesticides in boys.ObjectivesTo determine the association between pesticide exposure and reproductive health of boys.MethodsWe conducted a cross-sectional study in rural South Africa of boys living on and off farms. The study included a questionnaire (demographics, general and reproductive health, phyto-estrogen intake, residential history, pesticide exposures, exposures during pregnancy); and a physical examination that included sexual maturity development ratings; testicular volume; height, weight, body mass index; and sex hormone concentrations.ResultsAmong the 269 boys recruited into the study, 177 (65.8%) were categorized as farm (high pesticide exposures) and 98 (34.2%) as non-farm residents (lower pesticide exposures). Median ages of the two groups were 11.3 vs 12.0 years, respectively (p < 0.05). After controlling for confounders that included socioeconomic status, farm boys were shorter (regression coefficient (RC) = − 3.42 cm; 95% confidence interval (CI): − 6.38 to − 0.45 cm) and weighed less (RC = − 2.26 kg; CI: − 4.44 to − 0.75 kg). The farm boys also had lower serum lutenizing hormone (RC = − 0.28 IU/L; CI: − 0.48 to − 0.08 IU/L), but higher serum oestradiol (RC = 8.07 pmol/L; CI: 2.34–13.81 pmol/L) and follicle stimulating hormone (RC = 0.63 IU/L; CI: 0.19–1.08 U/L).ConclusionsOur study provides evidence that farm residence is associated with adverse growth and reproductive health of pubertal boys which may be due to environmental exposures to hormonally active contemporary agricultural pesticides.     

Do EU pesticide standards promote environmentally-friendly production of fresh export vegetables in developing countries? The evidence from Kenyan green bean industry

Developed countries are major markets for developing country fresh produce. Demand by developed country consumers for spotless produce has encouraged developing country consumers to rely increasingly on pesticides in producing fresh export vegetables. However developed country pesticide standards enacted in response to reports of increased farmer and farm worker pesticide poisoning and the food safety scandals of the 1980s and 1990s require changes in the way growers use pesticides. The EU has especially developed stringent food safety standards relating to, among other things, pesticide usage. Under EU pesticide standards (EU-PS) farmers are trained by their buyers on safe use of pesticides and then closely monitored under contract. This paper looks at the impact of these standards on developing country farmers’ use of alternative pest management practices, pesticide protective clothing and the actual usage of pesticides. It finds that compliance with EU-PS increases the use of alternative pest management practices and protective clothing. However, EU-PS has mixed effect on the quantity of pesticides used. The paper also finds that farmer’s education and access to information play an important role in the use of alternative pest management practices. The paper concludes that EU-PS encourage the use of alternative pest management practices and pesticide protective gear in production of fresh export vegetables. The findings imply that EU-PS promote environmentally-friendly methods of production of fresh export vegetables in developing countries.     

Pre- and postnatal exposures to pesticides and neurodevelopmental effects in children living in agricultural communities from South-Eastern Spain

BackgroundChildrens exposure to neurotoxic compounds poses a major problem to public health because of their actively developing brain that makes them highly vulnerable. However, limited information is available on neuropsychological effects in children associated with pre- and postnatal exposures to pesticides.ObjectiveTo evaluate the association between current and pre- and postnatal exposures to pesticides and their effects on neurodevelopment in children aged 6–11 years living in agricultural communities from South-Eastern Spain.MethodsAn ambispective study was conducted on 305 children aged 6–11 years randomly selected from public schools of the study area. Current exposure to organophosphate pesticides was assessed measuring children's urinary levels of dialkylphosphates (DAPs). Both prenatal and postnatal residential exposure to pesticides was estimated by developing a geographical information system (GIS) technology-based index that integrated distance-weighted measure of agricultural surface, time-series of crop areas per municipality and year, and land-use maps. Neuropsychological performance was evaluated with the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). The association of pre- and postnatal and current pesticide exposure with WISC-IV scale scores was assessed using multivariate linear regression models and generalized estimating equation (GEE) models, respectively.ResultsGreater urinary DAP levels were associated with a poorer performance on intelligence quotient and verbal comprehension domain, with effects being more prominent in boys than in girls. The influence of an increase in 10 ha per year in crop surface around the child's residence during the postnatal period was associated with decreased intelligence quotient, processing speed and verbal comprehension scores. As regards prenatal exposure to pesticides, a poor processing speed performance was observed. These effects were also more prominent in boys than in girls.ConclusionsOur results suggest that postnatal exposure to pesticides can negatively affect children's neuropsychological performance. Prenatal exposure was weakly associated to neurodevelopment impairment.     

Urinary concentrations of organophosphate and carbamate pesticides in residents of a vegetarian community

Few population studies have measured urinary levels of pesticides in individuals with vegan, vegetarian, or organic diets. The objectives of this study were to evaluate whether a vegan/vegetarian diet was associated with increased exposure to organophosphate and carbamate pesticides, and to evaluate the impact of organic consumption on pesticide exposure in vegans and vegetarians. In the current pilot study conducted in 2013–2014, we collected spot urine samples and detailed 24 h recall dietary data in 42 adult residents of Amirim, a vegetarian community in Northern Israel. We measured urinary levels of non-specific organophosphate pesticide metabolites (dialkylphosphates, (DAPs)) and specific metabolites of the current-use pesticides chlorpyrifos (3,5,6-trichloro-2-pyridinol (TCPy)), propoxur (-isopropoxyphenol (IPPX)), and carbaryl (1-naphthol). Six DAP metabolites were detected in between 67 and 100% of urine samples, with highest geometric mean concentrations for dimethylphosphate (19.2 μg/g). Creatinine-adjusted median concentrations of total DAPs and of TCPy were significantly higher in Amirim residents compared to the general Jewish population in Israel (0.29 μmol/g compared to 0.16, p < 0.05 for DAPs and 4.32 μg/g compared to 2.34 μg/g, p < 0.05 for TCPy). Within Amirim residents, we observed a positive association between vegetable intake and urinary TCPy levels (rho = 0.47, p < 0.05) and lower median total dimethyl phosphate levels in individuals reporting that > 25% of the produce they consume is organic (0.065 μmol/L compared to 0.22, p < 0.05). Results from this pilot study indicate relatively high levels of urinary organophosphate pesticide metabolite concentrations in residents of a vegetarian community, a positive association between vegetable intake and urinary levels of a chlorpyrifos specific metabolite, and lower levels of total dimethyl phosphate in individuals reporting higher intake of organic produce. Results suggest that consumption of organic produce may offer some protection from increased exposure to organophosphate pesticide residues in vegetarians.     

Occupational exposure to pesticides and Parkinson's disease: A systematic review and meta-analysis of cohort studies

ObjectivesTo systematically review available cohort studies and estimate quantitatively the association between occupational exposure to pesticides and Parkinson's disease (PD).MethodsStudies were identified from a MEDLINE search through 30 November 2011 and from the reference lists of identified publications. Relative risk (RR) estimates were extracted from 12 studies published between 1985 and 2011. Meta-rate ratio estimates (mRR) were calculated according to fixed and random-effect meta-analysis models. Meta-analyses were performed on the whole set of data and separate analyses were conducted after stratification for gender, exposure characterisation, PD cases identification, geographic location, reported risk estimator and cohort study design.ResultsA statistically significant increased risk of PD was observed when all studies were combined (mRR = 1.28; 95% confidence interval [CI]: 1.03–1.59) but there was a high heterogeneity and inconsistency among studies. The highest increased risks were observed for studies with the best design, i.e. reporting PD diagnosis confirmed by a neurologist (mRR = 2.56; CI: 1.46–4.48; n = 4), for cohort studies reporting incidence of PD (mRR = 1.95; CI: 1.29–2.97; n = 3) as well as for prospective cohorts (mRR = 1.39; CI: 1.09–1.78; n = 6). A significant increased risk was also seen for banana, sugarcane and pineapple plantation workers (mRR = 2.05; CI: 1.23–3.42; n = 2).ConclusionsThe present study provides some support for the hypothesis that occupational exposure to pesticides increases the risk of PD.     

Application of an improved method for the analysis of pesticides and their metabolites in the urine of farmer applicators and their families

As the annual use of pesticides in the United States has escalated, public health agencies have become increasingly concerned about chronic pesticide exposure. However, without reliable, accurate analytical methods for biological monitoring, low-level chronic exposures are often difficult to assess. A method for measuring simultaneously the urinary residues of as many as 20 pesticides has been significantly improved. The method uses a sample preparation which includes enzyme digestion, extraction, and chemical derivatization of the analytes. The derivatized analytes are measured by using gas chromatography coupled with isotope-dilution tandem mass spectrometry. The limits of detection of the modified method are in the high pg/L - low μg/L range, and the average coefficient of variation (CV) of the method was below 20% for most analytes, with approximately 100% accuracy in quantification. This method was used to measure the internal doses of pesticides among selected farmer applicators and their families. Definite exposure and elimination patterns (i.e., an increase in urinary analyte levels following application and then a gradual decrease to background levels) were observed among the farmer applicators and many of the family members whose crops were treated with carbaryl, dicamba, and 2,4-D esters and amines. Although the spouses of farm workers sometimes exhibited the same elimination pattern, the levels of the targeted pesticides or metabolites found in their urine were not outside the ranges found in the general U.S. population (reference range). The farmer applicators who applied the pesticides and some of their children appeared to have higher pesticide or metabolite levels in their urine than those found in the general U.S. population, but their levels were generally comparable to or lower than reported levels in other occupationally exposed individuals. These results, however, were obtained from a nonrandom sampling of farm residents specifically targeted to particular exposures who may have altered their practices because they were being observed; therefore, further study is required to determine if these results are representative of pesticide levels among residents on all farms where these pesticides are applied using the same application techniques. Using this method to measure exposure in a small nonrandom farm population allowed differentiation between overt and background exposure. In addition, the important role of reference-range information in distinguishing between various levels of environmental exposure was reaffirmed.     

Parental occupational exposure to pesticides as risk factor for brain tumors in children and young adults: A systematic review and meta-analysis

ObjectiveTo examine the potential association between parental occupational exposure to pesticides and the occurrence of brain tumors in children and young adults.MethodsStudies identified from a MEDLINE search through 15 January 2013 and from the reference lists of identified publications were submitted to a systematic review and meta-analysis. Relative risk estimates were extracted from 20 studies published between 1974 and 2010. Most of the retrieved studies involved farm/agricultural jobs. Summary ratio estimates (SR) were calculated according to fixed and random-effect meta-analysis models. Separate analyses were conducted after stratification for study design, exposure parameters, disease definition, geographic location and age at diagnosis.ResultsStatistically significant associations were observed for parents potentially exposed to pesticides in occupational settings and the occurrence of brain tumor in their offspring after combining all case–control studies (summary odds ratio [SOR]: 1.30; 95%: 1.11, 1.53) or all cohort studies (summary rate ratio [SRR]: 1.53; 95% CI: 1.20, 1.95). Significantly increased risks were seen for prenatal exposure windows, for either exposed parent, for exposure defined as to pesticides as well as by occupational/industry title, for astroglial brain tumors and after combining case–control studies from North America or cohort studies from Europe.ConclusionsThis meta-analysis supports an association between parental occupational exposure to pesticides and brain tumors in children and young adults, and adds to the evidence leading to the recommendation of minimizing (parental) occupational exposure to pesticides. These results must, however, be interpreted with caution because the impact of work-related factors others than pesticide exposure is not known.     

Environmental and human risk hierarchy of pesticides: A prioritization method,based on monitoring,hazard assessment and environmental fate

A pesticide prioritization approach was developed and implemented in the Pinios River Basin of Central Greece. It takes under consideration the Level of Environmental Risk containing information on the frequency of occurrence of pesticides above environmental thresholds, the intensity of this occurrence and the spatial distribution as well as information about the fate and behavior of pesticides in the environment and the potential to have adverse impact on humans' health. Original 3-year monitoring data from 102 Stationary Sampling Sites located on rivers and their tributaries, reservoirs, streams and irrigation/drainage canals giving rise to a collection of 2382 water samples resulting in 7088 data sets, were included in this integrated prioritization study.Among 302 monitored active ingredients, 119 were detected at least once and the concentrations found in the aquatic systems for 41% of compounds were higher than the respective lowest Predicted Non-Effect Concentration (PNEC) values. Sixteen and 5 pesticides were found with risk ratios (MEC_max/PNEC) above 10 (high concern) and 100 (very high concern), respectively. However, pesticides with maximum Measured Environmental Concentration (MEC_max) values exceeding by 1000 times the respective lowest PNEC values were also found which were considered of extremely high concern; in the latter group were included prometryn, chlorpyrifos, diazinon, λ-cyhalothrin, cypermethrin, α-cypermethrin deltamethrin, ethalfluralin and phosmet. The sensitivity of the analytical methods used in the monitoring study was considered inadequate to meet the toxicological endpoints for 32 pesticides. The widest distribution of occurrence in the Stationary Sampling Sites of the monitoring program was found for the pesticides, prometryn, fluometuron, terbuthylazine, S-metolachlor, chlorpyrifos, diphenylamine, acetochlor, alachlor, 2,4-D, etridiazole, imidacloprid and lindane (γ-ΗCH). Among the 27 priority pesticides included in the Directive 2013/39/EU, in the present study 13 pesticides were considered as candidates for River Basin Specific Pollutants (RBSP) for the River Basin of Pinios. Among the 30 pesticide specific pollutants that were established by the Greek authorities, in the present study only 6 were considered as candidates for RBSP for the river basin of Pinios. As a result of the implementation of the prioritization approach developed in this study a total of 71 pesticides were identified as being RBSP for the river basin of Pinios. The higher Level of Environmental Risk was found to be exerted by the organophosphorus insecticide chlorpyrifos, followed by lindane and prometryn.The present study provides background information for important decisions to be made concerning the selection of pesticides which should be included in the target analyte list of new monitoring and screening programs of surface water quality in the Pinios River Basin. In addition, the prioritization approach proposed here can be useful for the development of River Basin Management Plans.     

Recalculating GHG emissions saving of palm oil biodiesel

In 2010, the Renewable Energy Directive (RED) came into force in the EU and establishes a framework for achieving legally binding greenhouse gas (GHG) emission reductions. Only sustainable biofuels can be counted towards Member State targets. The aim of this paper is to calculate realistic and transparent scenario-based CO₂-emission values for the GHG emissions savings of palm oil fuel compared with fossil fuel. Using the calculation scheme proposed by the RED, we derive a more realistic overall GHG emissions saving value for palm oil diesel by using current input and output data of biofuel production (e.g. in South-East Asia). We calculate different scenarios in which reliable data on the production conditions (and the regarding emission values during the production chain) of palm oil diesel are used. Our results indicate values for the GHG emissions savings potential of palm oil biodiesel not only above the 19 % default and 36 % typical value published in RED but also above the 35 % sustainable threshold. Our findings conclude the more accurate GHG emissions saving value for palm oil feedstock for electricity generation to be 52 %, and for transportation biodiesel between 38.5 and 41 %, depending on the fossil fuel comparator. Our results confirm the findings by other studies and challenge the official typical and default values published in RED. As a result, the reliability of the Directive to support the EU’s low-carbon ambitions is being undermined, exposing the EU and commission to charges of trade discrimination and limiting the ability of Member States to achieve their legally binding GHG emission reductions.     

EPA's SHEDS-multimedia model: Children's cumulative pyrethroid exposure estimates and evaluation against NHANES biomarker data

The U.S. EPA's SHEDS-Multimedia model was applied to enhance the understanding of children's exposures and doses to multiple pyrethroid pesticides, including major contributing chemicals and pathways. This paper presents combined dietary and residential exposure estimates and cumulative doses for seven commonly used pyrethroids, and comparisons of model evaluation results with NHANES biomarker data for 3-PBA and DCCA metabolites. Model input distributions were fit to publicly available pesticide usage survey data, NHANES, and other studies, then SHEDS-Multimedia was applied to estimate total pyrethroid exposures and doses for 3–5 year olds for one year variability simulations. For dose estimations we used a pharmacokinetic model and two approaches for simulating dermal absorption. SHEDS-Multimedia predictions compared well to NHANES biomarker data: ratios of 3-PBA observed data to SHEDS-Multimedia modeled results were 0.88, 0.51, 0.54 and 1.02 for mean, median, 95th, and 99th percentiles, respectively; for DCCA, the ratios were 0.82, 0.53, 0.56, and 0.94. Modeled time-averaged cumulative absorbed dose of the seven pyrethroids was 3.1 nmol/day (versus 8.4 nmol/day for adults) in the general population (residential pyrethroid use and non-use homes) and 6.7 nmol/day (versus 10.5 nmol/day for adults) in the simulated residential pyrethroid use population. For the general population, contributions to modeled cumulative dose by chemical were permethrin (60%), cypermethrin (22%), and cyfluthrin (16%); for residential use homes, contributions were cypermethrin (49%), permethrin (29%), and cyfluthrin (17%). The primary exposure route for 3–5 year olds in the simulated residential use population was non-dietary ingestion exposure; whereas for the simulated general population, dietary exposure was the primary exposure route. Below the 95th percentile, the major exposure pathway was dietary for the general population; non-dietary ingestion was the major pathway starting below the 70th percentile for the residential use population. The new dermal absorption methodology considering surface loading had some impact, but did not change the order of key pathways.     

Biomarkers of pesticide exposure and diabetes in the 1999–2004 National Health and Nutrition Examination Survey

The associations of 8 pesticides and pesticide metabolites with total diabetes (diagnosed and undiagnosed) and pre-diabetes (glycohemoglobin 5.7–6.4%) were evaluated using the National Health and Nutrition Examination Survey (NHANES), 1999–2004. Six of the pesticides were found to be associated with total diabetes in separate adjusted logistic regressions. These pesticides and pesticide metabolites were beta-hexachlorocyclohexane, p,p′-DDE, p,p′-DDT, oxychlordane, trans-nonachlor, and heptachlor epoxide. When the number of compounds elevated was tested, 4 or more, of the 6, elevated had an odds ratio of 4.99 (95% CI 1.97–12.61) compared to none elevated. When the 6 compounds were tested together in a single combined adjusted logistic regression only oxychlordane, a metabolite of chlordane, and heptachlor epoxide, a metabolite of heptachlor, were significantly associated with total diabetes. In the combined adjusted logistic regression, oxychlordane ≥ 14.5 ng/g lipid adjusted had an odds ratios of 1.90 (95% CI 1.09–3.32) compared to oxychlordane < 14.5 ng/g lipid adjusted, and heptachlor epoxide ≥ 14.6 ng/g lipid adjusted had an odds ratio of 1.70 (95% CI 1.16–2.49) compared to heptachlor epoxide < 14.6 ng/g lipid adjusted. Heptachlor epoxide and p,p′-DDT were significantly associated with pre-diabetes in separate adjusted logistic regressions. When these 2 compounds were tested together only heptachlor epoxide remained significantly associated with pre-diabetes. The evidence supporting the relationship between pesticides and pesticide metabolites, with diabetes, was strongest for heptachlor epoxide and oxychlordane, intermediate for p,p′-DDT, and least for beta-hexachlorocyclohexane, p,p′-DDE, and trans-nonachlor. Mirex and dieldrin were not associated with total diabetes or pre-diabetes.     

Pesticide use practices among smallholder vegetable farmers in Ethiopian Central Rift Valley

Pesticide use is a common practice to control pests and diseases in vegetable cultivation, but often at the expense of the environment and human health. This article studies pesticide-buying and use practices among smallholder vegetable farmers in the Central Rift Valley of Ethiopia, using a practice perspective. Through in-depth interviews and observations, data were collected from a sample of farmers, suppliers and key governmental actors. The results reveal that farmers apply pesticides in violation of the recommendations: they use unsafe storage facilities, ignore risks and safety instructions, do not use protective devices when applying pesticides, and dispose containers unsafely. By applying a social practice approach, we show that these pesticide-handling practices are steered by the combination of the system of provision, the farmers’ lifestyle and the everyday context in which pesticides are being bought and used. Bringing in new actors such as environmental authorities, suppliers, NGOs and private actors, as well as social and technological innovations, may contribute to changes in the actual performance of these pesticides buying and using practices. This article argues that a practice approach represents a promising perspective to analyse pesticide handling and use and to systematically identify ways to change these.     

Mechanistic polychlorinated biphenyl exposure modeling of mothers in the Canadian Arctic: the challenge of reliably establishing dietary composition

BackgroundTraditional food (TF) consumption represents the main route of persistent organic pollutant (POP) exposure for indigenous Arctic Canadians. Ongoing dietary transitions away from TFs and toward imported foods (IFs) may contribute to decreasing POP exposures observed in these groups.MethodsTo explore this issue, we combined the global fate and transport model GloboPOP and the human food chain bioaccumulation model ACC-Human Arctic to simulate polychlorinated biphenyl (PCB) exposure in two indigenous Arctic Canadian communities from the Inuvik region, Northwest Territories and Baffin region, Nunavut. Using dietary survey information from initial (1996–98) and follow-up (2005–07) biomonitoring campaigns in Inuvik and Baffin, we simulated PCB exposures (PCB-118, -138, -153, and -180) for each individual study participant and also whole study populations.ResultsTF intake rates, particularly of marine mammals (MMs), were the most important predictors of modeled PCB exposure, while TF consumption did not associate consistently with measured PCB exposures. Further, reported mean TF intake increased from baseline to follow-up in both Inuvik (from 8 to 183 g d^− 1) and Baffin (from 60 to 134 g d^− 1), opposing both the expected dietary transition direction and the observed decrease in human PCB exposures in these communities (ΣPCB Inuvik: from 43 to 29 ng g lipid^− 1, ΣPCB Baffin: from 213 to 82 ng g lipid^− 1). However dietary questionnaire data are frequently subject to numerous biases (e.g., recall, recency, confirmation), and thus casts doubt on the usefulness of these data.ConclusionsUltimately, our model's capability to reproduce historic PCB exposure data in these two groups was highly sensitive to TF intake, further underscoring the importance of accurate TF consumption reporting, and clarification of the role of dietary transitions in future POP biomonitoring of indigenous Arctic populations.