Male-mediated infertility in sons of building painters and gardeners: A nationwide register-based follow-up study

► Concern that epigenetic pathways may mediate effects of chemical exposure from one generation to the next. ► Studied whether sons of gardeners and building painters have increased risk of infertility in comparison with sons of bricklayers, carpenters and electricians by use of Danish registers (N=22,978). ► In main analyses, neither sons of gardeners nor sons of painters had increased risk of infertility. ► From sub-analyses that only included the subset of participants with the smallest risk of paternal exposure misclassification, we cannot exclude a reduction in fertility among sons of building painters. To investigate whether sons of gardeners and building painters have increased risk of infertility in comparison with sons of bricklayers, carpenters and electricians. Participants were men born 1965–1984 in Denmark whose fathers the year before birth had worked as gardeners, painters, bricklayers, carpenters or electricians (N=22,978). Cases of infertility were identified by Danish registers, and participants were followed-up for up to 24 years after their 20th birthday. Sons of gardeners did not have increased risk of infertility. Hazard ratios for sons of painters fluctuated around the null in main analyses but were 1.6 (98% CI: 1.0–2.5) and 1.7 (95% CI: 0.9–3.2) in the subset of participants with smallest risk of paternal exposure misclassification. Working as gardener or building painter was not related to increased risk of infertility among the next generation of males in main analyses. However, inherent limitations in data may have attenuated true associations.