Declining male fertility rates have become a significant global health concern, with potential implications for individual reproductive health and broader societal demographics. Increasing evidence from animal and human studies suggests a strong link between occupational exposure to endocrine-disrupting chemicals (EDCs) and impaired sperm quality. EDCs are exogenous substances that interfere with the normal function of the endocrine system, potentially disrupting hormonal balance and reproductive processes. Occupational settings, particularly in industries like agriculture, manufacturing, and waste management, often involve exposure to complex mixtures of these EDCs, raising significant concerns about their cumulative impact on male reproductive health. The aim of this study is to determine the associations between occupational exposure to EDCs and sperm quality using data from the CHAPS-UK study. This was a multi-centre case-referent study of male infertility that recruited men who were part of couples attempting conception without success for at least 12 months. The study involved 2,249 men who were recruited over the period of 37 months, between January 1999 and February 2002. Risk factors associated with low sperm motility and adverse sperm morphology were identified, including glycol ether exposure. Exposure to potential EDCs will be estimated for their men and their mothers using a previously developed job exposure matrix, and the associations between exposure and sperm quality (concentration, motility, and morphology) will be determined.

In addition to synthesising the existing knowledge on this topic, this study seeks to bridge critical gaps in understanding the reproductive toxicity of EDCs. The findings are expected to provide valuable insights into preventing and mitigating EDC-related health risks, guiding regulatory policies and public health interventions to reduce exposure and protect reproductive health.