Prediagnostic serum concentrations of organochlorine pesticides and non-Hodgkin lymphoma: A nested case-control study in the Norwegian Janus Serum Bank Cohort.

•Serum levels of 11 organochlorine pesticide analytes were measured in a cohort.•Levels in this Norwegian cohort exceeded those observed in other European cohorts.•These levels were examined in relation to incident non-Hodgkin lymphoma (NHL).•Risks of NHL were elevated in upper quartiles of β-HCH, but with no apparent trend.•A few inverse associations were found in subgroup analyses, possibly due to diet.