SPL18 ENDOCRINE DISRUPTING CHEMICALS: IMPACT ON THE ENVIRONMENT AND HUMAN HEALTH
Authors: de Jager Christiaan , Patrick Sean , Aneck-Hahn Natalie , Bornman Riana 
Published: July 2024

The global epidemiological landscape has undergone a significant transformation, witnessing a shift towards non-communicable diseases (NCDs) as the predominant causes of mortality and morbidity, displacing infectious diseases. This transition is evident both in Africa and worldwide, arising from a multifaceted interplay of genetic and environmental factors. Notably, exposure to a diverse array of environmental hazards (encompassing contaminated water sources, air pollution, pesticides, agrochemicals, heavy metals, and industrial chemicals), contributes substantially to the escalating incidence of disease. Of particular concern within this milieu is the presence of endocrine disrupting chemicals (EDCs), which disrupt hormonal function and exacerbate susceptibility to diseases across various life stages.

EDCs pervade ecosystems through various pathways, including contamination of the food chain and leaching from food contact materials, underscoring the imperative to understand their collective impact on human, animal, and environmental health. Particularly pertinent are contemporary insecticides, notably those employed in malaria vector control, which exhibit endocrine disrupting properties. Despite awareness of their adverse effects on endocrine function and persistence in the environment, certain nations, such as South Africa, continue to rely on insecticides like DDT (1,1,1-trichloro-2,2-bis(chlorodiphenyl)ethane) for indoor residual spraying (IRS).

Our objective is to synthesize the findings from several of our studies examining the effects of pesticides on human health. These studies evaluate outcomes such as semen parameters, sperm DNA damage, and epigenetic changes. Additionally, we investigate the impact of exposure to other environmental EDCs on reproductive health in animals.

Exposures to insecticides, primarily occurring through low-level environmental or occupational contact, are associated with adverse male reproductive health due to their EDC activity. Our research specifically delves into the endocrine disrupting properties of insecticides used in malaria vector control in Africa. These compounds accumulating in the environment and posing risks to both wildlife and human fertility and health.

Our investigations unveil a troubling trend of sustained DDT exposure over a 13-year period, despite a decline in exposure levels. This persistent exposure adversely impacts seminal parameters and chromatin integrity, suggesting potential reproductive health implications, particularly in malaria-prone areas, where synergistic and additive effects with known EDCs may exacerbate the situation. Furthermore, new findings confirmed paternal exposure to DDT correlates with adverse sperm health, potentially affecting offspring health through epigenetic modifications linked to fertility, neurodevelopment, and hormone regulation.

Analyses of fresh produce from South African markets highlight the presence of multiple pesticide residues, some of which exhibit estrogenic activity, potentially contributing to adverse health effects. Similar concerns arise from assessments of bottled water and food contact materials, which contain compounds like phthalates, bisphenol A (BPA), and nonylphenol, associated with human health risks. These findings underscore the need for comprehensive health risk assessments of complex EDC mixtures within the food chain, considering potential additive and synergistic effects of multiple contaminants, including pesticides, agrochemicals, industrial chemicals, personal care products, and emerging environmental contaminants. Exposure can occur in various settings, whether it's in the workplace or at home, highlighting the importance of educational initiatives and the critical need to mitigate such exposure.