Outdoor, indoor, and personal exposure to VOCs in children

Abstract

We measured volatile organic compound (VOC) exposures in multiple locations for a diverse population of children who attended two inner-city schools in Minneapolis, Minnesota. Fifteen common VOCs were measured at four locations: outdoors (O), indoors at school (S), indoors at home (H), and in personal samples (P). Concentrations of most VOCs followed the general pattern O approximately equal to S < P less than or equal to H across the measured microenvironments. The S and O environments had the smallest and H the largest influence on personal exposure to most compounds. A time-weighted model of P exposure using all measured microenvironments and time-activity data provided little additional explanatory power beyond that provided by using the H measurement alone. Although H and P concentrations of most VOCs measured in this study were similar to or lower than levels measured in recent personal monitoring studies of adults and children in the United States, p-dichlorobenzene was the notable exception to this pattern, with upper-bound exposures more than 100 times greater than those found in other studies of children. Median and upper-bound H and P exposures were well above health benchmarks for several compounds, so outdoor measurements likely underestimate long-term health risks from children's exposure to these compounds.

Figure 1. Scatter plot of correlation between a 48-hr P VOC exposure and a time-weighted average of VOC exposure from major microenvironments where children spent time each day.

Figure 2. Age-adjusted regression results showing variability (95% CIs) in P VOC concentrations for study design (e.g., school, demographic categories), source (e.g., use of cleaning products), or exposure modification (e.g., ventilation) variables. Vent, ventilation. Interaction terms are displayed only if statistically significant: season, winter 2000 vs. spring 2000; school, Whittier vs. Lyndale; sex, female vs. male; African American, Somali immigrant, Hispanic, and Southeast Asian vs. other (including Caucasian); travel, > 1.5 hr on highway or road today; cleaners, > 0 hr spent using cleaning supplies today; cigarettes, > 0 cigarettes smoked in your presence today; Vent, > 12 hr doors and windows were left open for ventilation today; room deodorizers; cleaners × Vent; room deodorizers × Vent.

Figure 3. Age-adjusted regression results showing variability (95% CIs) in H VOC concentrations for study design (e.g., demographic categories), source (e.g., use of cleaning products), or exposure modification (e.g., ventilation) variables. Vent, ventilation. Interaction terms are displayed only if statistically significant: season, winter 2000 vs. spring 2000; African American, Somali immigrant, Hispanic, and Southeast Asian vs. other (including white); cleaners, > 0 hr spent using cleaning supplies today; cigarettes, > 0 cigarettes smoked in your presence today; Vent, > 12 hr doors and windows left open for ventilation today; room deodorizers; cleaners × Vent.