Personal exposure to ultrafine particles: The influence of time-activity patterns

The average exposure to particle number concentration was higher for women during both summer and winter (Summer: women 1.8 × 104 part. cm− 3; men 9.2 × 103 part. cm− 3; Winter: women 2.9 × 104 part. cm− 3; men 1.3 × 104 part. cm− 3), which was likely due to the time spent undertaking cooking activities. Staying indoors after cooking also led to higher alveolar-deposited surface area dose for both women and men during the winter time (9.12 × 102 and 6.33 × 102 mm2, respectively), when indoor ventilation was greatly reduced. The effect of cooking activities was also detected in terms of women's dose intensity (dose per unit time), being 8.6 and 6.6 in winter and summer, respectively. On the contrary, the highest dose intensity activity for men was time spent using transportation (2.8 in both winter and summer).