Reduced Seminal Parameters Associated With Environmental DDT Exposure andp,p′‐DDE Concentrations in Men in Chiapas, Mexico: A Cross‐Sectional Study

Abstract

ABSTRACT:In response to mounting concerns about the endocrine-disrupting influence of environmental chemicals on human health, this epidemiological study was initiated to test the hypothesis that nonoccupational exposure to the estrogenic pesticide 1,1,1-trichloro-2,2-bis(chlorodiphenyl)ethane (DDT) affects male reproductive parameters. One hundred and sixteen men aged 27 years (SD ϭ 8.2) living in malaria endemic-areas in Chiapas (Mexico), where DDT was sprayed until 2000, participated in a cross-sectional study. Semen analyses were conducted according to World Health Organization methods and a quality control program was followed. DDT exposure was defined as the level of blood plasma p,pЈ-dichlorodiphenyl dichloroethylene (DDE), the major metabolite of DDT. The p,pЈ-DDE concentration adjusted for total lipids was 100 times higher than that reported for nonexposed populations at 45 plus or minus 32 g/g (mean Ϯ SD). Crude regression analysis showed that several sperm motion parameters, including the percentage of motile sperm, decreased with higher p,pЈ-DDE concentrations (␤ ϭ Ϫ8.38; P ϭ .05 for squared motility), and the percentage of sperm with morphological tail defects increased with higher plasma p,pЈ-DDE concentration (␤ ϭ 0.003; P ϭ .017). Insufficient sperm chromatin condensation was observed in 46.6% of participants, and the most severe category of incomplete DNA condensation was also positively correlated with p,pЈ-DDE concentration (r ϭ .223; P ϭ .044). Therefore, nonoccupational exposure to DDT, as assessed by plasma p,pЈ-DDE concentrations, is associated with poorer semen parameters in men, indicating adverse effects on testicular function and/or the regulation of reproductive hormones. Previously, a causal role of environmental toxicants in human male infertility has been lacking because observed effects have been the result of unusually high exposures, either occupationally or as a result of industrial accidents, resulting in unprecedented controversy (reviewed by Cheek & McLachlan, Environmental hormones and the male reproductive system. J Androl. 1998;19:5). This is the first epidemiological study demonstrating effects after nonoccupational exposures to DDT. Based on these findings, the effect of DDT on male reproductive health should not be ignored.

The Thyroid Disruptor 1,1,1-Trichloro-2,2-Bis(p-Chlorophenyl)-Ethane Appears to Be an Uncompetitive Inverse Agonist for the Thyrotropin Receptor

“…Comprehensive literature is available for DDT due to the worldwide use of this compound as an insecticide. Serum levels of 10 M have been measured in subjects chronically exposed to DDT (Chen et al, 2005;De Jager et al, 2006). This being the case, it is predictable that any thyroid dysfunction following chronic exposure to DDT could be caused, at least in part, by a direct interaction of this insecticide with the TSHr (Brucker-Davis, 1998).…”

High levels of DDT in breast milk: Intake, risk, lactation duration, and involvement of gender

“…Now, 24 years later, it is disconcerting that the highest ΣDDT level in breast milk yet measured from South Africa (5.2 mg/l wm and 140 mg/kg mf; Table 1) was found in a breast milk sample collected about 60 km away from the previous highest ΣDDT. Despite numerous scientific assessments recommending that safe and sustainable alternatives to DDT should be urgently investigated and deployed (De Jager et al, 2006;De Jager et al, 2009;Eskenazi et al, 2009;Bornman et al, 2010;Bouwman et al, 2011), a relatively affluent African country is in a position to do much more to reduce exposures or to move away from DDT. It must be acknowledged however, that a previous attempt to switch from DDT to pyrethroids failed (Hargreaves et al, 2003;Maharaj et al, 2005), and that the expectations of proof of safety and sustainability of alternatives have probably increased due to that failure.…”

Male reproductive organs are at risk from environmental hazards

“…Several studies from the Limpopo Province in South Africa and studies from Mexico have consistently indicated impaired semen quality associated with environmental dichlorodiphenyl-ethylene (DDT)-exposure among people living in endemic malarias areas [43,44]. The question whether malarial fever could explain the results has unfortunately not been addressed.…”