Declining trends in serum cotinine levels in US worker groups: the power of policy.

Objective: To explore trends in cotinine levels in US worker groups.
Methods: Using NHANES III data, serum cotinine levels of US workers not smokers nor exposed to secondhand smoke (SHS) at home were evaluated for trends by occupational/industrial and race/ethnicity-gender sub-groups.
Results: Decreases from 1988 to 2002 ranged from 0.08 to 0.30 ng/mL (67% to 85% relative decrease), with largest absolute reductions in: blue-collar and service occupations; construction/manufacturing industrial sectors; non-Hispanic Black male workers.
Conclusions: All worker groups had declining serum cotinine levels. Most dramatic reductions occurred in sub-groups with the highest before cotinine levels, thus disparities in SHS workforce exposure are diminishing with increased adoption of clean indoor laws. However, Black male workers, construction/manufacturing sector workers, and blue-collar and service workers have the highest cotinine levels. Further reductions in SHS exposure will require widespread adoption of workplace clean air laws without exemptions.