Lower acetylcholinesterase activity among children living with flower plantation workers

Sex and adrenal hormones in association with insecticide biomarkers among adolescents living in ecuadorian agricultural communities

BACKGROUND

Organophosphate, pyrethroid, and neonicotinoid insecticides have resulted in adrenal and gonadal hormone disruption in animal and in vitro studies; limited epidemiologic evidence exists in humans. We assessed relationships of urinary insecticide metabolite concentrations with adrenal and gonadal hormones in adolescents living in Ecuadorean agricultural communities.

METHODS

In 2016, we examined 522 Ecuadorian adolescents (11-17y, 50.7% female, 22% Indigenous; ESPINA study). We measured urinary insecticide metabolites, blood acetylcholinesterase activity (AChE), and salivary testosterone, dehydroepiandrosterone (DHEA), 17β-estradiol, and cortisol. We used general linear models to assess linear (β = % hormone difference per 50% increase of metabolite concentration) and curvilinear relationships (β2 = hormone difference per unit increase in squared ln-metabolite) between ln-metabolite or AChE and ln-hormone concentrations, stratified by sex, adjusting for anthropometric, demographic, and awakening response variables. Bayesian Kernel Machine Regression was used to assess non-linear associations and interactions.

RESULTS

The organophosphate metabolite malathion dicarboxylic acid (MDA) had positive associations with testosterone (βboys = 5.88% [1.21%, 10.78%], βgirls = 4.10% [-0.02%, 8.39%]), and cortisol (βboys = 6.06 [-0.23%, 12.75%]. Para-nitrophenol (organophosphate) had negatively-trending curvilinear associations, with testosterone (β2boys = -0.17 (-0.33, -0.003), p = 0.04) and DHEA (β2boys = -0.49 (-0.80, -0.19), p = 0.001) in boys. The neonicotinoid summary score (βboys = 5.60% [0.14%, 11.36%]) and the neonicotinoid acetamiprid-N-desmethyl (βboys = 3.90% [1.28%, 6.58%]) were positively associated with 17β-estradiol, measured in boys only. No associations between the pyrethroid 3-phenoxybenzoic acid and hormones were observed. In girls, bivariate response associations identified interactions of MDA, Para-nitrophenol, and 3,5,6-trichloro-2-pyridinol (organophosphates) with testosterone and DHEA concentrations. In boys, we observed an interaction of MDA and Para-nitrophenol with DHEA. No associations were identified for AChE.

CONCLUSIONS

We observed evidence of endocrine disruption for specific organophosphate and neonicotinoid metabolite exposures in adolescents. Urinary organophosphate metabolites were associated with testosterone and DHEA concentrations, with stronger associations in boys than girls. Urinary neonicotinoids were positively associated with 17β-estradiol. Longitudinal repeat-measures analyses would be beneficial for causal inference.

Non-carcinogenic health risk from carbamate pesticide exposure of toddlers living in agricultural areas of Thailand

Toddlers in agricultural areas may be athave risk from pesticide exposure . A cross-sectional study was conducted with 130 toddlers and their caregivers. Face-to-face interviews were done to gather information about exposure factors. A wipe sampling technique was used to collect carbamate residues on each toddler's hands and feet. Results showed that there were carbamate residues on all wipe samples (100%), with a median concentration of 30.47 micrograms per sample (hands and feet). Carbamate residues detected on toddlers' hands and feetwere significantly associated (p < 0.05) with many factors, including the toddlers' relationships with caregivers, the education level of caregivers, the household incomes, the gender of toddlers, the frequency of following caregivers to farms, the frequency of foot washing, daytime activities, and playing durations. The health risk from dermal carbamate exposurewas above the acceptable range (HI = 3.244). Preventive measures should be considered to reduce toddlers' pesticide exposure in agricultural areas.

Urinary Glyphosate, 2,4-D and DEET Biomarkers in Relation to Neurobehavioral Performance in Ecuadorian Adolescents in the ESPINA Cohort

BACKGROUND

Herbicides are the most used class of pesticides worldwide, and insect repellents are widely used globally. Yet, there is a dearth of studies characterizing the associations between these chemical groups and human neurobehavior. Experimental studies suggest that glyphosate and 2,4-dichlorophenoxyacetic acid (2,4-D) herbicides can affect neurobehavior and the cholinergic and glutamatergic pathways in the brain. We aim to assess whether herbicides and insect repellents are associated with neurobehavioral performance in adolescents.

METHODS

We assessed 519 participants (11-17 years of age) living in agricultural communities in Ecuador. We quantified urinary concentrations of glyphosate, 2,4-D, and two N,N-diethyl-meta-toluamide (DEET) insect repellent metabolites [3-(diethylcarbamoyl)benzoic acid (DCBA) and 3-(ethylcarbamoyl)benzoic acid (ECBA)] using isotope-dilution mass spectrometry. We assessed neurobehavioral performance using 9 subtests across 5 domains (attention/inhibitory control, memory/learning, language, visuospatial processing, and social perception). We characterized the associations using generalized estimating equations and multiple imputation for metabolites below detection limits. Models were adjusted for demographic and anthropometric characteristics, urinary creatinine, and sexual maturation. Mediation by salivary cortisol, dehydroepiandrosterone, 17 β -estradiol , and testosterone was assessed using structural equation modeling.

RESULTS

The mean of each neurobehavioral domain score was between 7.0 and 8.7 [standard deviation (SD) range: 2.0-2.3]. Glyphosate was detected in 98.3% of participants, 2,4-D in 66.2%, DCBA in 63.3%, and ECBA in 33.4%. 2,4-D was negatively associated with all neurobehavioral domains, but statistically significant associations were observed with attention/inhibition [score difference per 50% higher metabolite concentration ( β ) = - 0.19 95% confidence interval (CI): - 0.31 , - 0.07 ], language [β = - 0.12 (95% CI: - 0.23 , - 0.01 )], and memory/learning [β = - 0.11 (95% CI: - 0.22 , 0.01)]. Glyphosate had a statistically significant negative association only with social perception [β = - 0.08 (95% CI: - 0.14 , - 0.01 )]. DEET metabolites were not associated with neurobehavioral performance. Mediation by gender and adrenal hormones was not observed.

CONCLUSION

This study describes worse neurobehavioral performance associated with herbicide exposures in adolescents, particularly with 2,4-D. Replication of these findings among other pediatric and adult populations is needed. https://doi.org/10.1289/EHP11383.

Para-occupational exposure to chemical substances: a systematic review

Today, many health problems related to work have overshadowed workers and their families. In the meantime, chemicals are among the risk factors that have created many problems due to para-occupational exposure. In para-occupational exposures, family members are exposed to work pollutants transferred to the home environment. This study was conducted to investigate para-occupational exposure to chemicals. To conduct this systematic review, databases such as "Web of Science", "Google Scholar", "Scopus", and "SID" were used. Relevant articles in these databases were extracted by searching keywords such as "take-home exposure", "para-occupational exposure", and "chemicals" from 2000 to 2022. To extract the required data, all parts of the articles were reviewed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA 2020). Among the 44 identified articles, 23 were selected as final articles, of which 10 were related to agriculture workers and their families, and 13 were related to other occupations. These studies mainly investigated para-occupational exposure to pesticides (14 studies) and metals (four studies). Also, contaminated work clothes, the washing place of contaminated clothes, and storage of working clothes, equipment, and chemicals were proposed as the main routes of contamination transmission. As a result of these para-occupational exposures, problems like neuro-behavioral disorders in children, end-stage renal disease, black gingival borders, and autism spectrum disorder were created or aggravated. Limiting the transmission routes and taking measures such as training and providing facilities like devoting places for washing and storing clothes in the workplaces can decrease this type of exposure.

Pyrethroid and Chlorpyrifos Pesticide Exposure, General Intellectual Abilities, and Executive Functions of School Children from Montevideo, Uruguay

Children's developing brains are susceptible to pesticides. Less is known about the effect of exposure to chlorpyrifos and pyrethroids on executive functions (EF). We measured urinary 3,5,6-trichloro-2-pyridinol (TCPy), a metabolite of chlorpyrifos, and urinary 3-phenoxybenzoic acid (3-PBA), a general, nonspecific metabolite of pyrethroids in first-grade children from Montevideo, Uruguay (n = 241, age 80.6 ± 6.4 months, 58.1% boys). EFs were assessed with the Intra-dimensional/Extra-dimensional shift (IED), Spatial Span (SSP), and Stockings of Cambridge (SOC) tests from the Cambridge Neuropsychological Test Automated (CANTAB) Battery. General intellectual ability (GIA) was assessed using the Woodcock-Muñoz Cognitive battery. Median (range) urinary TCPy and 3-PBA levels were 16.7 (1.9, 356.9) ng/mg of creatinine and 3.3 (0.3, 110.6) ng/mg of creatinine, respectively. In multivariable generalized linear models, urinary TCPy was inversely associated with postdimensional errors on the IED task β [95% CI]: -0.11 [-0.17, -0.06]. Urinary 3-PBA was inversely associated with the total number of trials -0.07 [-0.10, -0.04], and the total number of errors -0.12 [-0.18, -0.07] on the IED task. When TCPy and 3-PBA were modeled together, the associations did not differ from single-metabolite models. We found no evidence of effect modification by blood lead level (BLL). Pesticide exposure may affect EF performance in urban children.

Concurrent urinary organophosphate metabolites and acetylcholinesterase activity in Ecuadorian adolescents

BACKGROUND

Organophosphates are insecticides that inhibit the enzymatic activity of acetylcholinesterase (AChE). Because of this, AChE is considered a physiological marker of organophosphate exposure in agricultural settings. However, limited research exists on the associations between urinary organophosphate metabolites and AChE activity in children.

METHODS

This study included 526 participants from 2 exams (April and July-October 2016) of ages 12-17 years living in agricultural communities in Ecuador. AChE activity was measured at both examinations, and organophosphate metabolites, including para-nitrophenol (PNP), 3,5,6-trichloro-2-pyridinol (TCPy), and malathion dicarboxylic acid (MDA) were measured in urine collected in July-October. We used generalized estimating equation generalized linear model (GEEGLM), adjusting for hemoglobin, creatinine, and other demographic and anthropometric covariates, to estimate associations of urinary metabolite concentrations with AChE activity (July-October) and AChE% change between April and July-October.

RESULTS

The mean (SD) of AChE and AChE% change (April vs July-October) were 3.67 U/mL (0.54) and -2.5% (15.4%), respectively. AChE activity was inversely associated with PNP concentration, whereas AChE% change was inversely associated with PNP and MDA. There was evidence of a threshold: difference was only significant above the 80th percentile of PNP concentration (AChE difference per SD increase of metabolite = -0.12 U/mL [95%CI: 0.20, -0.04]). Likewise, associations with AChE% change were significant only above the 80th percentile of TCPy (AChE % change per SD increase of metabolite = -1.38% [95%CI: 2.43%, -0.32%]) and PNP -2.47% [95%CI: 4.45%, -0.50%]). PNP concentration at ≥80th percentile was associated with elevated ORs for low AChE activity of 2.9 (95% CI: 1.5, 5.7) and for AChE inhibition of ≤ -10% of 3.7 (95% CI: 1.4, 9.8).

CONCLUSIONS

Urinary organophosphate metabolites, including PNP, TCPy and MDA, particularly at concentrations above the 80th percentile, were associated with lower AChE activity among adolescents. These findings bring attention to the value of using multiple constructs of pesticide exposure in epidemiologic studies.

Time after a peak-pesticide use period and neurobehavior among ecuadorian children and adolescents: The ESPINA study

BACKGROUND

Limited evidence exists regarding transient neurobehavioral alterations associated with episodic pesticide exposures or agricultural pesticide spray periods. We previously observed that children examined soon after a pesticide spray period (the Mother's Day flower harvest [MDH]) had lower neurobehavioral performance than children examined later. The present study builds on our previous work by incorporating longitudinal analyses from childhood through adolescence.

METHODS

We examined participants in agricultural communities in Ecuador (ESPINA study) during three periods: July-August 2008 (N = 313, 4-9-year-olds); April 2016 (N = 330, 11-17-year-olds); July-October 2016 (N = 535, 11-17-year-olds). Participants were examined primarily during a period of low floricultural production. Neurobehavior was assessed using the NEPSY-II (domains: Attention/Inhibitory Control, Language, Memory/Learning, Visuospatial Processing, and Social Perception). Linear regression and generalized linear mixed models were used to examine cross-sectional and longitudinal associations between examination date (days) after the MDH and neurobehavioral outcomes, adjusting for demographic, anthropometric, and socio-economic variables.

RESULTS

Participants were examined between 63 and 171 days after the MDH. Mean neurobehavioral domain scores ranged from 1.0 to 17.0 (SD_range = 2.1-3.1) in 2008 and 1.0 to 15.5 (SD_range = 2.0-2.3) in 2016. In cross-sectional analyses (2016 only; N = 523), we found significant or borderline positive associations between time after the MDH and Attention/Inhibitory Control (difference/10 days [β] = 0.22 points [95% CI = 0.03, 0.41]) and Language (β = 0.16 points [95% CI = -0.03, 0.34]). We also observed positive, longitudinal associations (2008-2016) with Attention/Inhibitory Control (β = 0.19 points [95% CI = 0.04, 0.34]) through 112 days after the harvest and Visuospatial Processing (β = 3.56, β-quadratic = -0.19 [95% CI: -0.29, -0.09]) through 92 days.

CONCLUSIONS

Children examined sooner after the harvest had lower neurobehavioral performance compared to children examined later, suggesting that peak pesticide spray seasons may transiently affect neurobehavior followed by recovery during low pesticide-use periods. Reduction of pesticide exposure potential for children during peak pesticide-use periods is advised.

A review on pesticides in flower production: A push to reduce human exposure and environmental contamination

In several countries, flower import regulations are restricted to food security, by establishing maximum residue limits (MRL) for pesticides in flower-based food products and biosafety, in order to limit the circulation of vectors, pests and exotic species across borders. In this context, the lack of limits on pesticides in flower-products for ornamental purposes can influence the pesticide overuse in production areas, as well as the transfer of contaminated products between countries. Therefore, the purpose of this review was to discuss possible adverse effects on human and environmental health of pesticides used in floriculture, evaluating regulations on the use of these pesticides in the main importing and flower-producing countries. This review included 92 documents. The use of 201 compounds was identified by interviews and analytical measurements. Among them, 93 are banned by the European Union (EU), although 46.3 % of these compounds have been identified in samples from European countries. Latin American countries have a large number of scientific publications on pesticides in flower production (n = 51), while the EU and China have less studies (n = 24) and the United States and Japan have no studies. Regarding adverse health effects, poorer neurobehavioral development, reproductive disorders, congenital malformations and genotoxicity have been reported for residents of flower production areas and workers throughout the flower production cycle. Studies including water samples show overuse of pesticides, while environmental impacts are related to water and air contamination, soil degradation and adverse effects on the reproduction and development of non-target organisms. This review points out that the absence of MRL for non-edible flowers can be crucial for the trade of contaminated products across borders, including pesticides banned in importing countries. Furthermore, setting limits on flowers could reduce the use of pesticides in producing countries.

Testosterone, estradiol, DHEA and cortisol in relation to anxiety and depression scores in adolescents

Background Adrenal and sex hormone dysregulation have been independently associated with increased depression and anxiety. Cortisol can modify production of sex hormones and hormone-mood associations. This study evaluated associations and interplay of sex and adrenal hormones with depression and anxiety. Methods We assessed 545 Ecuadorian adolescents (11-17y, 50.4% female, ESPINA) for depression and anxiety symptoms using standardized scales. Testosterone, cortisol, dehydroepiandrosterone (DHEA), and estradiol (boys only) were measured in saliva. We performed logistic regression modeling to calculate odds ratios (OR) of elevated depression or anxiety (scores ≥60) comparing participants with low (<10th percentile) and elevated hormones (≥90th percentile) to normal concentrations (10th-90th percentile). Effect modification by cortisol and testosterone was assessed. Models adjusted for demographic, anthropometric, and circadian measures. Results In all participants, elevated testosterone (OR [95%CI:]=1.78 [0.98, 3.23]) and cortisol (OR=1.69 [0.95, 2.99]) were marginally associated with elevated anxiety scores. In boys, elevated estradiol was associated with elevated depression (OR=4.75 [1.95, 11.56]) and anxiety scores (OR=2.43 [1.01, 5.84]). In linear regression, estradiol was positively associated with depression (difference/10% hormone increase (β=0.45 [0.15, 0.75]) and anxiety scores (β=0.42 [0.13, 0.72]). Higher cortisol levels strengthened the depression association with estradiol in boys (β=0.54 [0.12, 0.96]), and with testosterone (β= -0.19 [-0.35, -0.03]) and DHEA (β= -0.12 [-0.22, -0.02]) in girls. Testosterone also modified associations. Limitations This was a cross-sectional analysis. Discussion Elevated testosterone, cortisol, and estradiol (≥90th percentile) were associated with altered mood. Cortisol and testosterone were considerable effect modifiers to the associations of most hormones with depression and anxiety.

COVID-19 and children's health in the United States: Consideration of physical and social environments during the pandemic

Public health measures necessary to counteract the coronavirus disease 2019 (COVID-19) pandemic have resulted in dramatic changes in the physical and social environments within which children grow and develop. As our understanding of the pathways for viral exposure and associated health outcomes in children evolves, it is critical to consider how changes in the social, cultural, economic, and physical environments resulting from the pandemic could affect the development of children. This review article considers the environments and settings that create the backdrop for children's health in the United States during the COVID-19 pandemic, including current threats to child development that stem from: A) change in exposures to environmental contaminants such as heavy metals, pesticides, disinfectants, air pollution and the built environment; B) changes in food environments resulting from adverse economic repercussion of the pandemic and limited reach of existing safety nets; C) limited access to children's educational and developmental resources; D) changes in the social environments at the individual and household levels, and their interplay with family stressors and mental health; E) social injustice and racism. The environmental changes due to COVID-19 are overlaid onto existing environmental and social disparities. This results in disproportionate effects among children in low-income settings and among populations experiencing the effects of structural racism. This article draws attention to many environments that should be considered in current and future policy responses to protect children's health amid pandemics.

Acetylcholinesterase activity and thyroid hormone levels in Ecuadorian adolescents living in agricultural settings where organophosphate pesticides are used

BACKGROUND

Organophosphates are frequently applied insecticides that inhibit acetylcholinesterase (AChE) activity resulting in cholinergic overstimulation. Limited evidence suggests that organophosphates may alter thyroid hormone levels, although studies have yielded inconsistent findings. We aimed to test the associations between AChE activity, a physiological marker of organophosphate exposure, and thyroid function in adolescents.

METHODS

We included information of 80 adolescent participants (ages 12-17y in 2016, 53% male) growing up in agricultural settings in Ecuador. We measured fingerstick erythrocytic AChE activity and hemoglobin concentration, and concurrent serum thyroid stimulating hormone (TSH) and free-T4 (fT4) concentrations. General linear models were used to test associations which adjusted for demographic and anthropometric variables. TSH associations were further adjusted for fT4.

RESULTS

The mean (SD) AChE, TSH and fT4 levels were 3.77 U/mL (0.55), 2.82 μIU/ml (1.49) and 1.11 ng/dl (0.13), respectively. Lower AChE activity, indicating greater organophosphate exposure, was marginally associated with greater fT4 concentrations (difference per SD decrease in AChE activity (β) = 0.03 ng/dL, [90% CI: 0.00, 0.06]) but not with TSH (β = -0.01 μIU/ml, [-0.38, 0.36]). Gender modified the AChE-TSH association (p = 0.03). In girls, lower AChE activity was associated with higher fT4 levels (β=0.05 ng/dL [0.01, 0.10]) and lower TSH concentrations (β = -0.51 μIU/ml, [-1.00, -0.023]). No associations were observed in boys.

DISCUSSION

These cross-sectional findings suggest that alterations in the cholinergic system from organophosphate exposures can increase fT4 levels coupled with a beyond-compensatory downregulation of TSH in female adolescents. This is the first study to characterize these associations in adolescents.

Associations of acetylcholinesterase inhibition between pesticide spray seasons with depression and anxiety symptoms in adolescents, and the role of sex and adrenal hormones on gender moderation

BACKGROUND

Cholinesterase inhibitor pesticides, especially organophosphates, are endocrine disruptors and a few existing studies have linked self-reports of exposure with increased depression and anxiety. Some evidence suggests that associations may be stronger in women, but the mechanism of this gender difference is unclear. We assessed whether acetylcholinesterase (AChE) inhibition between 2 time points (reflecting greater cholinesterase inhibitor exposure) during different agricultural seasons in the year was associated with anxiety/depression symptoms.

METHODS

We examined 300 adolescents (ages 11-17y, 51% female) living near agricultural settings in Ecuador (ESPINA study) twice in 2016: April and July-October. We assessed AChE activity (finger stick), estradiol, testosterone, dehydroepiandrosterone, cortisol (saliva) and anxiety and depression scales (CDI-2 and MASC-2).

RESULTS

The mean (SD) depression and anxiety scores were 52.8 (9.3) and 58.1 (9.6), respectively. The median (25th, 75th percentile) AChE change (July-October vs April) was -3.94% (-10.45%, 5.13%). For every 10% decrease in AChE activity, there was a 0.96 unit (95%CI: 0.01, 1.90) increase in depression symptoms and an OR of elevated depression score of 1.67 (1.04, 2.66). These associations were stronger in girls (OR=2.72 [1.23, 6.00]) than boys (1.18 [0.59, 2.37]). Adjustment for cortisol, testosterone and dehydroepiandrosterone reduced gender differences by 18-62%. No associations were observed with anxiety.

DISCUSSION

Inhibition of AChE activity at 2 points in time during different pesticide spray periods was associated with greater depression symptoms, affecting girls more than boys. Gender differences may be partly explained by endocrine disruption. These findings suggest that AChE inhibition may transiently affect the mood of adolescents.

Exposure to environmental neurotoxic substances and neurodevelopment in children from Latin America and the Caribbean

Environmental (and occupational) exposure to neurotoxic substances is a worldwide problem that can affect children's neurodevelopment (ND). In Latin American and Caribbean (LAC) countries there are over 300 million children living under the threat of neurodevelopmental delays due to toxic environmental exposure. Large industrial centers, intense mining and agricultural activities, along with changing complex ecosystems constitute a mosaic that drives contamination of air, water and the food chain. Neurotoxic contaminants such as pesticides (organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, and manganese fungicides), chemicals of industrial use (phthalates), and metals (Hg, Pb, Al, As, F, Cd, Mo, Mn) are at the center of environmental exposure studies. Exposure to neurotoxic substances singly or in combination with other compounds or socioeconomic stressors (maternal education, socio-economic and nutritional status) intertwined with occupational and para-occupational exposure can affect ND (motor, cognition, behavior) of children. Significant negative effects of pesticides and neurotoxic elements on ND were found in all studied countries, affecting especially the less-privileged children from laboring families. Studies showed that exposures to the neurotoxicants in human milk are secondary to their more lasting effects during prenatal exposure. This review integrates exposure (prenatal and breastfeeding), metabolism, and ND effects of neurotoxicants. It highlights the overwhelming evidence showing that current levels of exposures are hazardous and detrimental to children's ND in LAC countries. The evidence indicates that a reduction in neurotoxicant exposure is essential to protect children's ND. Therefore, it is urgent to adopt policies and actions that prevent and remediate region-specific children's ND issues.

Residential proximity to greenhouse crops and pesticide exposure (via acetylcholinesterase activity) assessed from childhood through adolescence

BACKGROUND

Off-target drift of pesticides from farms increases the risk of pesticide exposure of people living nearby. Cholinesterase inhibitors (i.e. organophosphates and carbamates) are frequently used in agriculture and inhibit acetylcholinesterase (AChE) activity. Greenhouse agriculture is an important production method, but it is unknown how far pesticide drift from greenhouses can extend and expose people living nearby.

METHODS

This study included 1156 observations from 3 exams (2008, Apr, 2016 and Jul-Oct 2016) of 623 children aged 4-to-17 years living in agricultural communities in Ecuador. AChE, a physiological marker of cholinesterase inhibitor exposure, was measured in blood. Geographic positioning of greenhouses and homes were obtained using GPS receivers and satellite imagery. Distances between homes and the nearest greenhouse edge, and areas of greenhouse crops within various buffer zones around homes were calculated. Repeated-measures regression adjusted for hemoglobin and other covariates estimated change in AChE relative to distance from greenhouses.

RESULTS

The pooled mean (SD) of AChE activity was 3.58 U/mL (0.60). The median (25th-75th %tile) residential distance to crops was 334 m (123, 648) and crop area within 500 m of homes (non-zero values only) was 18,482 m2 (7115, 61,841). Residential proximity to greenhouse crops was associated with lower AChE activity among children living within 275 m of crops (AChE difference per 100 m of proximity [95% CI] = -0.10 U/mL [-0.20, -0.006]). Lower AChE activity was associated with greater crop area within 500 m of homes (AChE difference per 1000 m2 [95% CI] = -0.026 U/mL [-0.040, -0.012]) and especially within 150 m (-0.037 U/mL [-0.065, -0.007]).

CONCLUSIONS

Residential proximity to floricultural greenhouses, especially within 275 m, was associated with lower AChE activity among children, reflecting greater cholinesterase inhibitor exposure from pesticide drift. Analyses of residential proximity and crop areas near homes yielded complementary findings. Mitigation of off-target drift of pesticides from crops onto nearby homes is recommended.

Summary data of home proximity to the nearest greenhouse (floricultural) crops and areas of greenhouse crops around various distances from homes in agricultural settings in Ecuador

This article presents data of 623 children (1156 observations) between 4 and 17 years of age living in floricultural communities of Ecuador from 3 examination periods (2008, Apr 2016, and Jul-Oct 2016) as part of the study of Secondary Exposure to Pesticides among Children and Adolescents (ESPINA).We present geospatial data of residential distance to the nearest greenhouse crop and areas within various buffer sizes around homes of participants which is data used in the original research article: Suarez-Lopez JR, et al. "Residential proximity to greenhouse crops and pesticide exposure (via acetylcholinesterase activity) assessed from childhood through adolescence". These geospatial variables are related but different constructs of the potential for off-target drift of pesticides from crops onto homes nearby (via acetylcholinesterase activity) Understanding the associations between these distance and crop area variables is important as a growing number of investigations are using these constructs of off-target pesticide drift to characterize their associations with both exposure biomarkers and outcome measures. Geographic positioning of greenhouses and homes were obtained using GPS receivers and satellite imagery. Distances between homes and the nearest greenhouse edge, and areas of greenhouse crops within various buffer zones (0-150 m, 151-300 m, 310-500 m, 501-750 m, and 751-1000 m) around homes were calculated using Geographic Information System software. Beyond the dataset, we present demographic and anthropometric characteristics, and indicators of pesticide exposure of participants across categories of areas of greenhouse crops around homes for buffer sizes of 0-150 m around homes. We also present the distribution of areas of flower crops within various buffer zone sizes around children's homes and the correlation coefficients between household proximity to the nearest treated greenhouse crops and areas of flower crops within various buffer zones within 1000 m of homes.

Chemical reduction of chlorpyrifos driven by flavin mononucleotide functionalized titanium (IV) dioxide

For many decades, organohalide and organophosphate compounds have shown significant detrimental impact on the environment. Consequently, strategies for their remediation continue to be an area of emerging need. The reduction of the chlorpyrifos pesticide, a molecule that bears both organohalide and organophosphate functional groups, is an important area of investigation due to it toxic nature. In this report, we demonstrate the effectiveness of the biological molecule, flavin mononucleotide (FMN) toward chemically reducing chlorpyrifos. The FMN was found to be highly active when anchored to nanocrystalline TiO2 surfaces. The results show new directions toward the remediation of organic contaminants under mild reaction conditions.

Eliminating Take-Home Exposures: Recognizing the Role of Occupational Health and Safety in Broader Community Health

Toxic contaminants inadvertently brought from the workplace to the home, known as take-home or paraoccupational exposures, have often been framed as a problem that arises due to unsanitary worker behavior. This review article conceptualizes take-home exposures as a public health hazard by (i) investigating the history of take-home contaminants and how they have been studied, (ii) arguing that an ecosocial view of the problem is essential for effective prevention, (iii) summarizing key structural vulnerabilities that lead populations to be at risk, and (iv) discussing future research and prevention effort needs. This article reframes take-home exposures as one of many chronic pathways that contributes to persistent health disparities among workers, their families, and communities. Including the role of work in community health will increase the comprehensiveness of prevention efforts for contaminants such as lead and pesticides that contribute to environmental disparities.

Residential proximity to greenhouse agriculture and neurobehavioral performance in Ecuadorian children

BACKGROUND

Children living near greenhouse agriculture may have an increased risk of pesticide exposure due to drift or direct contact with pesticide-treated areas. However, little is known about whether this increased potential for chronic exposure may impair their neurodevelopment.

METHODS

We examined 307 children aged 4-9 years, living in agricultural communities in Ecuador (ESPINA study). The two exposures calculated were residential distance from the nearest flower plantation perimeter and flower plantation surface area within 100 m of homes. Five neurobehavioral domains were assessed: Attention/Inhibitory Control, Memory/Learning, Visuospatial processing and Sensorimotor (higher values reflect better performance). Low scores were defined according to the test's cut-offs. Models were adjusted for demographic, socio-economic and growth variables.

RESULTS

The mean (SD) residential distance to the nearest flower plantation was 446 m (344). Living 100 m closer to crops was associated with increased odds (OR [95% CI]) of low scores in the domains of Memory/Learning (1.24 [1.05, 1.46]) and Language (1.09 [1.00, 1.19]). Associations were strongest among children living within 50 m, having significantly lower scores in Language (-1.28 which is ~50% of a SD [-2.50, -0.06]), Attention/Inhibitory Control (-1.24 units, [-2.45, -0.04]), and Memory/Learning (-0.91, [-1.99, 0.17]), compared to children living farther than 500 m. Analyses of areas of flower crops near homes concurred with these findings.

CONCLUSIONS

Close residential proximity to greenhouse floricultural crops was associated with adverse neurobehavioral performance in Attention/Inhibitory Control, Language and Memory/Learning among children. This highlights the importance of reducing pesticide drift from plantations to nearby homes.

One-Hour Pilot Training to Prevent Workers From Taking Home Workplace Contaminants

Workers can accidentally transport chemical hazards from the workplace to the home, known as “take-home exposures.” Recent take-home lead-poisoning cases highlight the need for effective prevention training. A one-hour take-home prevention training was developed in partnership with a nonprofit. The training was administered and evaluated during two training sessions with twenty-one trainees. The training was composed of a lecture and interactive activities. An illustrated poster was used with different prevention actions within a story line to reduce take-home exposures under three categories: facilities with formal health and safety programs, small businesses, and outdoor work. The effectiveness and acceptability of the training was measured by a survey and pre- and posttraining exams. The second training exam responses showed a 14 percent (84 percent to 98 percent) increase in take-home prevention knowledge. Community-based prevention training could reduce the burden of chemical exposures on vulnerable workers and their families.

Blood pressure after a heightened pesticide spray period among children living in agricultural communities in Ecuador

INTRODUCTION

Agricultural pesticide spray periods increase the pesticide exposure potential of children living nearby and growing evidence indicates that they may affect children's health. We examined the association of time following a heightened agricultural production period, the Mother's Day flower harvest (May), with children's blood pressure (BP).

METHODS

We included cross-sectional information of 313 children ages 4-9 years in Ecuadorian agricultural communities (the ESPINA study). Examinations occurred during a period of low flower production, but within 63-100 days (mean = 81.5, SD = 10.9) following the Mother's Day harvest. BP was measured twice using a pediatric sphygmomanometer and BP percentiles appropriate for age, gender and height were calculated.

RESULTS

Participants were 51% male, 1.6% hypertensive and 7.7% had elevated BP. The mean (SD) BP percentiles were: systolic: 51.7 (23.9); diastolic: 33.3 (20.3). There was an inverse relationship between of time after the spray season with percentiles of systolic (difference [β] per 10.9 days after the harvest: -4.3 [95%CI: -6.9, -1.7]) and diastolic BP (β: -7.5 [-9.6, -5.4]) after adjusting for race, heart rate and BMI-for-age z-score. A curvilinear association with diastolic BP was observed. For every 10.9 days that a child was examined sooner after the harvest, the OR of elevated BP/hypertension doubled (OR: 2.0, 95% CI: 1.3, 3.1). Time after the harvest was positively associated with acetylcholinesterase.

CONCLUSIONS

Children examined sooner after a heightened pesticide spray period had higher blood pressure and pesticide exposure markers than children examined later. Further studies with multiple exposure-outcome measures across pesticide spray periods are needed.

Associations of acetylcholinesterase activity with depression and anxiety symptoms among adolescents growing up near pesticide spray sites

BACKGROUND

The cholinergic system has an important role in mood regulation. Cholinesterase inhibitor pesticides (e.g. organophosphates) appear to increase depression and anxiety symptoms in the few existing animal and human studies. Human studies have not described such associations using biomarkers of exposure and studies among children are needed.

METHODS

We studied 529 adolescents (ages 11-17y) in agricultural communities in the Ecuadorian Andes (ESPINA study). Acetylcholinesterase (AChE) activity was measured in a finger-stick sample. Anxiety and depression symptoms were assessed using the CDI-2 and MASC-2 (greater scores reflect greater internalizing symptoms). Models adjusted for age, gender, hemoglobin, income among others.

RESULTS

The median age was 14.38y and 51% were female. The mean (SD) of the following parameters were: AChE 3.7 U/mL (0.55), depression T-score 53.0 (9.4) and anxiety T-score: 57.6 (9.8). Lower AChE activity (reflecting greater cholinesterase inhibitor exposure) was associated with higher depression symptoms (difference per SD decrease of AChE [β [95% CI:]]: 1.09 [0.02, 2.16]), was stronger among girls (β = 1.61) than boys (β = 0.69), and among younger (<14.38y, β = 1.61) vs. older children (β = 0.57). The associations were strongest among girls <14.38y (β = 3.30 [0.54, 6.05], OR for elevated symptoms per SD decrease in AChE = 2.58 [1.26, 5.27]). No associations were observed with anxiety scores. Analyses of AChE change between 2008 and 2016 concurred with these findings.

DISCUSSION

We observed associations between a biomarker of pesticide exposure and children's depression symptoms. Lower AChE activity may create risk for depression in teenagers, particularly among girls during early adolescence.

Systematic Literature Review of the Take-Home Route of Pesticide Exposure via Biomonitoring and Environmental Monitoring

BACKGROUND

Exposure to pesticides via take-home can be an important pathway for farmworkers' families.

OBJECTIVE

The aim of this review was to summarize and analyze the literature published during the last decade of exposure to pesticides via take-home pathway in farmworkers' families.

METHODS

We conducted a systematic review to identify peer-reviewed articles of interest; only articles related to take-home pathway that included some sort of pesticide monitoring were considered for inclusion. Systematic reviews, literature reviews, and meta-analyses were excluded, resulting in a total of 39 articles elected for analysis. The articles were summarized based on the location of the study, population (sample size), pesticide analyzed, and type of sample.

RESULTS

The majority of the reviewed studies were conducted in the U.S., but there seems to be an increase in literature on pesticide take-home pathway in developing countries. Most of the articles provided evidence that farmworkers' families are exposed to pesticides at higher levels than non-farmworkers' families. The levels may depend on several factors such as seasonality, parental occupation, cohabitation with a farmworker, behavior at work/home, age, and gender. Community-based interventions disrupting the take-home pathway seem to be effective at reducing pesticide exposure.

DISCUSSION/CONCLUSION

The take-home pathway is an important contributor to overall residential exposures, but other pathways such as pesticide drift, indoor-residential applications, and dietary intake need to be considered. A more comprehensive exposure assessment approach is necessary to better understand exposures to pesticides.

Feasibility of Portable Fingerstick Cholinesterase Testing in Adolescents in South Texas

Adolescents are particularly vulnerable to the impacts of pesticide exposures, which can be assessed using surveys, environmental measurements, and biomonitoring. Biomonitoring of blood cholinesterase can be used to determine if an individual has been exposed to pesticides. A limitation of blood cholinesterase testing can be the use of a laboratory as well as time to receive results. In addition to laboratory tests, there are fingerstick cholinesterase (ChE) tests, which can eliminate the need for laboratory testing. Some populations, such as farmworkers, would benefit through fingerstick ChE tests. The objective of this pilot study is to determine the feasibility (eg, can the testing be used to assess ChE levels) of using fingerstick ChE testing in adolescent populations living along the Texas-Mexico border where adolescents who often engage in farm work live. A sub-objective was to explore differences in ChE levels by sex. The Model 400 Test-Mate ChE kit by EQM Research Inc (Cincinnati, OH) was used to assess for ChE inhibition in the participants, specifically acetylcholinesterase (AChE), which is 1 of the 2 ChE enzymes. During the postassessment, males had a mean AChE value of 3.75 U/mL (95% CI 3.51-3.98); whereas females had a mean AChE value of 2.86 U/mL (95% CI 2.64-3.08), which was statistically significant. Overall, the study supports the use of field ChE testing in adolescent populations with a small percentage (6.90%) refusing to complete ChE testing.

Exposure of chlorpyrifos in toddlers living in an agricultural area in Sakon Nakhon province, North-East Thailand

Purpose

Children living in agricultural areas are exposed to pesticides in their living areas and through activities of daily living. These exposures may lead to adverse health effects. The purpose of this paper is to investigate household environmental and behavioural factors associated with chlorpyrifos exposure and resultant adverse health effects in children living in an agricultural community.

Design/methodology/approach

A cross-sectional study was conducted including 65 toddlers (age of 12–36 months) and their parents were face-to-face interviewed from January to February 2016. Toddler’s hands and feet, toys and floors were wiped for chlorpyrifos residue analysis. The wipes were extracted and analysed by gas chromatography with a flame photometric detector, and blood cholinesterase activity was measured by the EQM Test-mate (model 400).

Findings

The average age (± standard deviation) of children was 19.9 (±5.9) months. Chlorpyrifos detections were 61.5 per cent (hands), 57.1 per cent (toys), 53.8 per cent (floors) and 30.8 per cent (feet). The highest chlorpyrifos residue concentration was detected on toy surface (3.022 µg/m2). Chlorpyrifos residues on hands and feet were positively correlated with concentrations on floors and toys (Spearman’s ρ, p<0.01). Multiple linear regression analysis revealed that more frequent hand washing (β=−0.236, p=0.067) and showering (β=−0.240, p=0.056) was negatively associated with chlorpyrifos residue on children’s body. House cleaning frequency was significantly associated with an increase in haemoglobin-adjusted erythrocyte cholinesterase (β=0.251, p<0.05).

Originality/value

Chlorpyrifos exposures found in the children household area through their activities and behaviours can cause several adverse health effects. The circumstances associated with chlorpyrifos exposure should be mitigated and reduced to improve the household environment of children living agricultural areas.

Home proximity to flower plantations and higher systolic blood pressure among children

BACKGROUND

Pesticide drift from agricultural plantations increases the chemical exposure potential of people living nearby. Some studies have described positive associations between pesticide exposures and blood pressure (BP) in adults, whereas limited evidence in children suggests negative associations. This study characterized the association between home proximity to plantations and BP among children living in a flower-growing county in Ecuador.

METHODS

We included 310 4-9-year-old children living in Pedro Moncayo County, Ecuador as part of The ESPINA study. We calculated age, gender and height-specific BP z-scores. Geographic coordinates of homes and flower plantations were collected using GPS receivers and satellite imagery. Exposure-outcome associations were analyzed using linear regression.

RESULTS

The mean home distance to the nearest flower plantation was 449 m (SD: 347) and the median plantation area within 150 m of participants' homes was 989 m² (25^th-75^Th percentile: 492-3164) among those with non-zero values. Children living closer to plantations had lower AChE activity. Systolic BP z-score increased with greater residential proximity to plantations (0.24 SD per 1000 m [95% CI: 0.01, 0.47]) and with greater areas of flower plantations within 150 m of homes (0.03 SD per 1000 m² [0.00, 0.06]), after adjusting for socio-economic, anthropometric and other factors. Further adjustment for acetylcholinesterase and hemoglobin strengthened these associations.

CONCLUSIONS

Proximity of homes to flower plantations and greater plantation areas within 150 m from homes were associated with higher systolic BP, independent of cholinesterase activity. This suggests that non-cholinesterase inhibitor pesticide drift from agricultural plantations may be sufficient to induce physiologic changes on children living nearby.

Organophosphate flame retardants in dust collected from United States fire stations

Firefighters are exposed to chemicals during fire events and we previously demonstrated that fire station dust has high levels of polybrominated diphenyl ethers (PBDEs). In conducting the Fire Station Dust Study, we sought to further characterize the chemicals to which firefighters could be exposed - measuring the emerging class of phosphorous-containing flame retardants (PFRs) in fire stations, for the first time, as well as PBDEs. Dust samples from 26 fire stations in five states were collected from vacuum-cleaner bags and analyzed for PFRs and PBDEs. PFR concentrations were found to be on the same order of magnitude as PBDE concentrations (maximum PFR: 218,000ng/g; maximum PBDE: 351,000ng/g). Median concentrations of tri-n-butyl phosphate (TNBP), tris (2-chloroisopropyl) phosphate (TCIPP), and tris(1,3-dichloroisopropyl)phosphate (TDCIPP) in dust from fire stations were higher than those previously reported in homes and other occupational settings around the world. Total PFR levels did not vary significantly among states. Levels of TDCIPP were higher in stations where vacuum cleaners were used to clean surfaces other than the floor. PBDE levels were comparable to those found in our previous study of 20 California fire stations and much higher than levels in California residences. PFR and PBDE levels in fire station dust are higher than in other occupational and residential settings, underscoring the need to identify and control sources of this contamination.

Acetylcholinesterase activity and time after a peak pesticide-use period among Ecuadorian children

PURPOSE

Mother's Day (May) is a holiday with substantial demand for flowers, associated with heightened flower production and escalated pesticide use. The effect of spray seasons on pesticide exposures of children living in agricultural communities but who do not work in agriculture is poorly understood. In this study, we estimated the association of time after Mother's Day harvest with children's acetylcholinesterase (AChE) activity. AChE is a physiological marker of organophosphate/carbamate pesticide exposures that may take up to 3 months to normalize after its inhibition.

METHODS

We examined 308 children, aged 4-9 years, in Ecuadorian agricultural communities during a low flower-production season but within 63-100 days (mean: 81.5 days, SD: 10.9) after Mother's Day harvest. We quantified AChE activity (mean: 3.14 U/mL, SD: 0.49) from a single finger-stick sample.

RESULTS

We observed positive linear associations between time after the harvest and AChE among participants living near plantations. The associations were strongest among participants living within 233 m [(0.15 U/mL (95% CI 0.02, 0.28)], slightly weaker among participants living within 234-532 m [0.11 U/mL (0.00, 0.23)], and not associated among participants at greater distances. Similar findings were observed across categories of areas of flower plantations within 500 m of homes.

CONCLUSIONS

These cross-sectional findings suggest that a peak pesticide-use period can decrease AChE activity of children living near plantations. These seasonal pesticide exposures could induce short- and long-term developmental alterations in children. Studies assessing exposures at multiple times in relation to pesticide spray seasons among children who do not work in agriculture are needed.

Review of take-home pesticide exposure pathway in children living in agricultural areas

BACKGROUND

Children of farmworkers may be chronically exposed to pesticides via the take-home exposure pathway.

OBJECTIVE

The goal of this review was to analyze scientific literature evaluating the role of the take-home pesticide exposure pathway in children of agricultural workers.

METHODS

A systematic review was undertaken and inclusion criteria were applied to identify original articles of interest. Of the 30 articles included in this review, some belonged to the same studies, resulting in a total of 23 studies. Eight studies assessed environmental samples, nine collected biological samples, and the remaining six analyzed both. Eleven studies compared pesticide levels between farm and non-farm families.

RESULTS

There is convincing evidence that children of farmworkers are exposed to pesticides at higher levels than "non-agricultural" children, even when residing in the same agricultural communities. These levels were shown to depend on the season, occupation, number of farmworkers per home, and type of crops. Other factors such as age, gender and, sex seem to also influence this pathway. Some studies have shown that pesticides used solely in agriculture are found only in households of farmworkers spraying these pesticides. Moreover, intervention studies have shown that behaviors among farmworkers can significantly lower exposure of people living in the same households as farmworkers.

DISCUSSION AND CONCLUSION

The evidence presented here raises concerns regarding health effects associated with exposure to pesticides in children living in agricultural communities, and indicates that strategies should be developed to reduce exposures in these populations.

Potential short-term neurobehavioral alterations in children associated with a peak pesticide spray season: The Mother's Day flower harvest in Ecuador

BACKGROUND

Exposures to cholinesterase inhibitor pesticides (e.g. organophosphates) have been associated with children's neurobehavioral alterations, including attention deficit and impulsivity. Animal studies have observed transient alterations in neurobehavioral performance in relation to cholinesterase inhibitor pesticide exposures; however, limited evidence exists regarding transient effects in humans.

METHODS

We estimated the associations between neurobehavioral performance and time after Mother's Day flower harvest (the end of a heightened pesticide usage period) among 308 4-to 9-year-old children living in floricultural communities in Ecuador in 2008 who participated in the ESPINA study. Children's neurobehavior was examined once (NEPSY-II: 11 subtests covering 5 domains), between 63 and 100days (SD: 10.8days) after Mother's Day harvest (blood acetylcholinesterase activity levels can take 82days to normalize after irreversible inhibition with organophosphates).

RESULTS

The mean (SD) neurobehavioral scaled scores across domains ranged from 6.6 (2.4) to 9.9 (3.3); higher values reflect greater performance. Children examined sooner after Mother's Day had lower neurobehavioral scores than children examined later, in the domains of (score difference per 10.8days, 95%CI): Attention/Inhibitory Control (0.38, 0.10-0.65), Visuospatial Processing (0.60, 0.25-0.95) and Sensorimotor (0.43, 0.10-0.77). Scores were higher with longer time post-harvest among girls (vs. boys) in Attention/Inhibitory Control.

CONCLUSIONS

Our findings, although cross-sectional, are among the first in non-worker children to suggest that a peak pesticide use period may transiently affect neurobehavioral performance, as children examined sooner after the flower harvest had lower neurobehavioral performance than children examined later. Studies assessing pre- and post-exposure measures are needed.

The Red Blood Cell Acetylcholinesterase Levels of Depressive Patients with Suicidal Behavior in an Agricultural Area

Long-term exposure to organophosphate pesticides (OPs) without acute poisoning can lead to various OPs. Environmental exposure to organophosphate pesticides may be associated with depression and suicide attempts in a population living in a rural agricultural area. Patients (n = 149) suffering from major depressive disorder (with and without attempted suicide) and a control group of healthy individuals (n = 64) who had been living in the same rural district for at least 1 year were selected. Red blood cell acetylcholine esterase (RBC-AChE) activity was examined as the basis of evaluating the degree of chronic environmental exposure to OPs residues. There were negative association between RBC-AChE activity levels and suicide attempts, the number of past suicide attempts and hopelessness levels in the depressive patients. The results of the study may support the idea that environmental exposure to OPs may be associated with mental health in individuals living in agricultural districts who are not farmers or working in occupations with access to OPs.

High levels of polybrominated diphenyl ethers in vacuum cleaner dust from California fire stations

Firefighters are exposed to chemicals during fire events and may also experience chemical exposure in their fire stations. Dust samples from used vacuum cleaner bags were collected from 20 fire stations in California and analyzed for polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) using gas chromatography-mass spectrometry. Median dust concentrations were higher for PBDEs (e.g., 47 000 ng/g for BDE-209) than for PAHs (e.g., 220 ng/g for benzo[a]pyrene) or PCBs (e.g., 9.3 ng/g for PCB-180). BDE-209 concentrations in dust from California fire stations were among the highest of any previously documented homes or occupational settings in the world. We examined factors such as the frequency of emergency responses, the number of fire vehicles on site, and building age, but we could not account for the high levels of BDE-209 observed in fire station dust. Based on the findings of our pilot study, we hypothesize that possible sources of BDE-209 in fire stations include contaminated ash tracked back from fire events via boots, clothing, and other equipment as well as specialized equipment treated with BDE-209, including turnout gear and fire vehicles. We suggest possible follow-up studies to confirm these hypotheses.

Acetylcholinesterase activity and neurodevelopment in boys and girls

BACKGROUND

Organophosphate exposures can affect children's neurodevelopment, possibly due to neurotoxicity induced by acetylcholinesterase (AChE) inhibition, and may affect boys more than girls. We tested the hypothesis that lower AChE activity is associated with lower neurobehavioral development among children living in Ecuadorian floricultural communities.

METHODS

In 2008, we examined 307 children (age: 4-9 years; 52% male) and quantified AChE activity and neurodevelopment in 5 domains: attention/executive functioning, language, memory/learning, visuospatial processing, and sensorimotor (NEPSY-II test). Associations were adjusted for demographic and socioeconomic characteristics and height-for-age, flower worker cohabitation, and hemoglobin concentration.

RESULTS

Mean ± standard deviation AChE activity was 3.14 ± 0.49 U/mL (similar for both genders). The range of scores among neurodevelopment subtests was 5.9 to 10.7 U (standard deviation: 2.6-4.9 U). Girls had a greater mean attention/executive functioning domain score than boys. In boys only, there were increased odds ratios of low (<9th percentile) neurodevelopment among those in the lowest tertile versus the highest tertile of AChE activity (odds ratios: total neurodevelopment: 5.14 [95% confidence interval (CI): 0.84 to 31.48]; attention/executive functioning domain: 4.55 [95% CI: 1.19 to 17.38], memory/learning domain: 6.03 [95% CI: 1.17 to 31.05]) after adjustment for socioeconomic and demographic factors, height-for-age, and hemoglobin. Within these domains, attention, inhibition and long-term memory subtests were most affected.

CONCLUSIONS

Low AChE activity was associated with deficits in neurodevelopment, particularly in attention, inhibition, and memory in boys but not in girls. These critical cognitive skills affect learning and academic performance. Added precautions regarding secondary occupational pesticide exposure would be prudent.

Acetylcholinesterase activity, cohabitation with floricultural workers, and blood pressure in Ecuadorian children

BACKGROUND

Acetylcholinesterase (AChE) inhibitors are commonly used pesticides that can effect hemodynamic changes through increased cholinergic stimulation. Children of agricultural workers are likely to have paraoccupational exposures to pesticides, but the potential physiological impact of such exposures is unclear.

OBJECTIVES

We investigated whether secondary pesticide exposures were associated with blood pressure and heart rate among children living in agricultural Ecuadorian communities.

METHODS

This cross-sectional study included 271 children 4-9 years of age [51% cohabited with one or more flower plantation workers (mean duration, 5.2 years)]. Erythrocyte AChE activity was measured using the EQM Test-mate system. Linear regression models were used to estimate associations of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate with AChE activity, living with flower workers, duration of cohabitation with a flower worker, number of flower workers in the child's home, and number of practices that might increase children's exposure to pesticides.

RESULTS

Mean (± SD) AChE activity was 3.14 ± 0.49 U/mL. A 1-U/mL decrease in AChE activity was associated with a 2.86-mmHg decrease in SBP (95% CI: -5.20, -0.53) and a 2.89-mmHg decrease in DBP (95% CI: -5.00, -0.78), after adjustment for potential confounders. Children living with flower workers had lower SBP (-1.72 mmHg; 95% CI: -3.53, 0.08) than other children, and practices that might increase exposure also were associated with lower SBP. No significant associations were found between exposures and heart rate.

CONCLUSIONS

Our findings suggest that subclinical secondary exposures to pesticides may affect vascular reactivity in children. Additional research is needed to confirm these findings.