S07-1 Development of a comprehensive job-exposure matrix on endocrine disrupting substances and the application in studies on hypospadias and cryptorchidism

Endocrine disruptors (EDs) have been described as exogenous substances that alter endocrine system functions and thereby cause adverse health effects, especially in fetal development of the male reproductive system. Many occupationally used substances have been considered potentially endocrine disrupting. Therefore, van Tongeren et al developed a job-exposure matrix (JEM) to assess occupational exposure to EDs in the UK, which was published in 2002. This JEM was -among others- applied to a small case-control study on hypospadias (congenital malformation of the penis; n = 56) and cryptorchidism (undescended testes; n = 78) nested within the Generation R cohort in the Netherlands. The results showed an association between cryptorchidism and paternal pesticide exposure only. In 2008–2009, we updated and further developed the JEM, which now consists of 10 main groups of potential EDs and 33 subgroups for 353 job titles. To facilitate assignment of exposure scores, we added 57 different exposure scenarios and provided examples of adjustments to make the JEM better suited for application outside the UK. Subsequently, this renewed JEM was used in several studies both in the Netherlands and elsewhere. Application to a case-control study including 305 boys with hypospadias, 200 boys with cryptorchidism, and 629 referents from the eastern part of the Netherlands led to slightly elevated odds ratios for paternal exposure to pesticides (cryptorchidism), phthalates, and copper (hypospadias). Maternal occupational exposure to organic solvents seemed to increase the risk of hypospadias, while cryptorchidism was associated with exposure to ethylene glycol ethers, alkylphenolic compounds, a number of different phthalates, pesticides, copper, and a few substances primarily used in cosmetics. Within Generation R, parental exposure to several categories of EDs was also associated with prolonged time-to-pregnancy among 2,774 couples, while JEM-based assignment of maternal exposure to PAHs, alkylphenolic compounds, phthalates, and pesticides seemed to influence fetal growth among 4,680 live born children.