Environmentally relevant concentrations of short chain chlorinated paraffins induce transgenerational reproductive toxicity associated with mitochondrial homeostasis disruption in Caenorhabditis elegans

Short-chain chlorinated paraffins have been classified as persistent organic pollutants (POPs) since 2017. Although previous findings have examined toxicity and health risks of SCCPs, their impacts on germ cells and non-exposed progeny remain unclear. Our results revealed that environmentally relevant concentrations (1 μg/L, 10 μg/L, 100 μg/L and 1000 μg/L) of SCCPs compromised proliferation and maturation of germ cells in parental Caenorhabditis elegans, and exhibited prolonged effects on non-exposed F1 and F2 generations. Whole genome sequencing data suggested the potential impact of SCCPs on genomic stability of germ cells. Transcriptomic analysis showed disrupted expression levels of mitochondrial genes, including many NADH dehydrogenases and mitochondrial genome encoded cytochrome C oxidases in P0 and F1 progeny, which might be associated with increased germ cell apoptosis. The findings highlight long-term impacts of SCCPs on environmental organisms, and suggest possible connections between mitochondrial homeostasis disruption and transgenerational toxicity of SCCPs.