Assessment of personal exposure to ozone in asthmatic children residing in Mexico City
Salud Pública de México
Assessment of personal exposure to ozone in asthmatic children residing in Mexico City. Salud Publica Mex 2008;50:67-75. Abstract Objective. A study was conducted to evaluate personal ozone exposure (O 3p ) among asthmatic children residing in Mexico City. Material and Methods. A total of 158 children were recruited from December 1998 to April 2000. On average, three O 3p measurements were obtained per child using passive badges. Time-activity patterns were recorded in a diary. Daily ambient
... y. Daily ambient ozone measurements (O 3a ) were obtained from the fixed station, according to children's residence. Levels of O 3a and ozone, weighted by time spent in different micro-environments (O 3w ), were used as independent variables in order to model O 3p concentrations using a mixed-effects model. Results. Mean O 3p was 7.8 ppb. The main variables in the model were: time spent indoors, distance between residence and fixed station, follow-up group, and two interaction terms (overall R 2 =0.50, p<0.05). Conclusions. The O 3w concentrations can be used as a proxy for O 3p , taking into account time-activity patterns and the place of residence of asthmatic Mexican children. Cortez-Lugo M, Sienra-Monge JJ, Romieu I. Evaluación de la exposición personal a Ozono en niños asmáticos de la Ciudad de México. Salud Publica Mex 2008;50:67-75.