Atmospheric concentrations of volatile, halogenated hydrocarbons (VHH) can be correlated with intensity of industrial or commercial activities and with demographic density. Measurements of VHHs were performed in Turin, Italy. The VHH indoor/outdoor contamination ratio was calculated, and VHH blood concentrations were measured during 1 yr in Turin, Italy. The results showed a typical primary pollutant trend: 18.1 micrograms/m3 during winter and 12.02 micrograms/m3 during summer. During the winter, the VHH indoor/outdoor contamination ratio showed a greater indoor presence (p = .0006) and a higher VHH blood concentration (0.71 vs. 0.22 micrograms/l). The indoor and outdoor atmospheric VHH concentrations provide the major sources of human daily intake, especially during winter.