Comparison of neurological health outcomes between two adolescent cohorts exposed to pesticides in Egypt

Abstract

Pesticide-exposed adolescents may have a higher risk of neurotoxic effects because of their developing brains and bodies. However, only a limited number of studies have addressed this risk among adolescents. The aim of this study was to compare neurological outcomes from two cohorts of Egyptian adolescents working as pesticide applicators. In 2005 and 2009, two cohorts of male adolescents working as pesticide applicators for the cotton crop were recruited from Menoufia Governorate, Egypt. The same application schedule and pesticides were used at both times, including both organophosphorus, and pyrethroid compounds. Participants in both cohorts completed three neurobehavioral tests, health and exposure questionnaires, and medical and neurological screening examinations. In addition, blood samples were collected to measure butyryl cholinesterase (BChE) activity. Pesticide applicators in both cohorts reported more neurological symptoms and signs than non-applicators, particularly among participants in the 2005 cohort (OR ranged from 1.18 to 15.3). Except for one test (Trail Making B), there were no significant differences between either applicators or non-applicators of both cohorts on the neurobehavioral outcome measures (p > 0.05). The 2005 cohort showed greater inhibition of serum BChE activity than the 2009 cohort (p < 0.05). In addition, participants with depressed BChE activity showed more symptoms and signs than others without BChE depression (p < 0.05). Our study is the first to examine the consistency of health outcomes associated with pesticide exposure across two cohorts tested at different times from the same geographical region in rural Egypt. This similar pattern of findings across the two cohorts provides strong evidence of the health impact of exposure of adolescents to pesticides.

Sex-Specific Neurotoxic Effects of Organophosphate Pesticides Across the Life Course

“…Also, adolescents in developing countries frequently work as pesticide applicators, increasing their risk for acute exposure to high levels of OPs and adverse effects due to chronic exposures [24,97–98]. Additionally, adolescent brains undergo rapid development due to hormonal and corresponding physiological changes associated with puberty, rendering them even more sensitive.…”

The impact of repeated organophosphorus pesticide exposure on biomarkers and neurobehavioral outcomes among adolescent pesticide applicators

“…However, the majority of investigations relied upon a single time-point comparison between an exposed and an unexposed group. Further, few studies examined the impact of exposure among adolescent (age 14–24, (Geiger and Castellino 2011)) applicators, although those investigations noted similar findings (Abdel Rasoul et al 2008; Eckerman et al 2007; Ismail et al 2017; Rohlman et al 2014). …”

Environmental Health Research in Africa: Important Progress and Promising Opportunities

“…Biomarkers of exposures to the organophosphorus pesticides, chlorpyrifos (CPF) and Profenofos (PFF), were evaluated in some studies by measuring urinary levels of 3,5,6-trichloro-2-pyridinol (TCPy), a specific CPF metabolite and 4-bromo-2-chlorophenol (BCP), a specific PFF metabolite (Singleton et al, 2015). Inhibition of blood butyryl cholinesterase (BChE) and acetylcholinesterase (AChE) activities are effect biomarkers that were also evaluated in several of the reviewed studies Khan et al, 2014;Rohlman et al, 2014;Singleton et al, 2015;Rohlman et al, 2016;Ismail et al, 2017a;Ismail et al, 2017b). DDE/DDT was often assayed using ELISA (Bimenya et al, 2010).…”

“…The in utero and early childhood effects of various pesticides and impact on long-term health highlights early life as a key susceptible time window for pesticide exposure. Adolescents working seasonally or during certain periods on farms may have a higher risk of neurotoxic effects of pesticide exposure because of their rapidly developing brains and bodies Ismail et al, 2017a;Ismail et al, 2017b). Because of the high morbidity and mortality associated with childhood and adolescent poisoning with pesticides (sometimes intentional), targeted prevention initiatives should be a high priority (Balme et al, 2010;Balme et al, 2012).…”