Salud Pública de México
Print version ISSN 0036-3634
RAMIREZ-AGUILAR, Matiana et al. Assessment of personal exposure to ozone in asthmatic children residing in Mexico City. Salud pública Méx [online]. 2008, vol.50, n.1, pp. 67-75. ISSN 0036-3634.
OBJECTIVE: A study was conducted to evaluate personal ozone exposure (O3p) among asthmatic children residing in Mexico City. MATERIAL AND METHODS: A total of 158 chil-dren were recruited from December 1998 to April 2000. On average, three O3p measurements were obtained per child using passive badges. Time-activity patterns were recorded in a diary. Daily ambient ozone measurements (O3a) were obtained from the fixed station, according to childrens residence. Levels of O3a and ozone, weighted by time spent in different micro-environments (O3w), were used as independent variables in order to model O3p concentrations using a mixed-effects model. RESULTS: Mean O3p 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 R2=0.50, p<0.05). CONCLUSIONS: The O3w concentrations can be used as a proxy for O3p, taking into account time-activity patterns and the place of residence of asthmatic Mexican children.
Keywords : personal measurements; ozone; asthmatics; Mexico City; activity patterns.