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 (ß) = 0.03 ng/dL, [90% CI: 0.00, 0.06]) but not with TSH (ß = -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 (ß=0.05 ng/dL [0.01, 0.10]) and lower TSH concentrations (ß = -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.

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.

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.

Agroecology and Health: Lessons from Indigenous Populations.

PURPOSE OF REVIEW: The article aims to systematize and disseminate the main contributions of indigenous ancestral wisdom in the agroecological production of food, especially in Latin America. For this purpose, it is necessary to ask whether such knowledge can be accepted by academia research groups and international forums as a valid alternative that could contribute to overcome the world's nutritional problems. RECENT FINDINGS: Although no new findings are being made, the validity of ancestral knowledge and agroecology is recognized by scientific research, and by international forums organized by agencies of the United Nations. These recommend that governments should implement them in their policies of development, and in the allocation of funds to support these initiatives. Agroecology and ancestral knowledge are being adopted by a growing number of organizations, indigenous peoples and social groups in various parts of the world, as development alternatives that respond to local needs and worldviews. Its productive potential is progressively being recognized at an international level as a model that contributes to improve the condition of people regarding nutritional food.