Different approaches to the assessment of human exposure to nitrogen dioxide.

The exposure of 15 subjects to NO2 was assessed using different approaches: (a) direct measurement of personal exposure, (b) calculation of weighted average exposure using data on time spent and concentrations measured at home, at work, in transit, and outdoors, (c) the same calculation but instead of actual concentrations, using concentrations measured in other homes in Zagreb (out of 90) situated in a district with a similar traffic density, and using the same cooking fuel. The best agreement with personal exposure was obtained for exposure under (b), but calculation with surrogate concentrations (c) also gave a fair approximation.