[Exposure to passive smoking in local health units of northern Italy before and after the enforcement of the smoking ban].

Objective: to assess smoking habits, environmental tobacco smoke (ETS) exposure and smoking attitudes of workers toward different possible institutional restrictions before and after the implementation of the new Italian legislation about the public health protection from passive smoking (L 3/2003).

Design: Descriptive study based on self-reported questionnaires (2004 and 2005) and indoor measurement of particulate matter (PM, 2004 and 2006).

Setting: Local health authority n.