To explore social correlates of opportunity-based suicide rates, the suicide rates by car exhaust per car & per capita were calculated for the 48 continental states of the USA for 1980. Suicide rates by car exhaust per car & per capita were associated positively with median family income, married women working part-time, latitude & alcohol consumption & negatively with percent black residents, church attendance, married women working full time & southernness. (3 refs.)