Polycyclic aromatic hydrocarbons: levels and phase distributions in preschool microenvironment

Area of Science:

• Environmental Science
• Air Quality Monitoring
• Public Health

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are common indoor air pollutants.
• Preschool environments may expose children to elevated PAH levels.
• Understanding PAH sources and distribution is crucial for health risk assessment.

Purpose of the Study:

• To quantify polycyclic aromatic hydrocarbons (PAHs) levels and phase distribution in indoor preschool air.
• To assess the contribution of outdoor PAH emissions to indoor air quality.
• To identify major sources of PAHs in the urban preschool environment.

Main Methods:

• Concurrent indoor and outdoor air sampling for gaseous and particulate PAHs (PM1 and PM2.5) over 35 days.
• Analysis of 18 priority PAHs, including dibenzo[a,l]pyrene and benzo[j]fluoranthene.
• Calculation of indoor/outdoor (I/O) ratios to determine outdoor influence.

Main Results:

• Total indoor PAH (ΣPAHs) concentrations ranged from 19.5 to 82.0 ng/m(3).
• Gaseous PAHs constituted 85% of total indoor PAHs.
• Particulate PAHs were mainly associated with PM1, with 5-ring PAHs being most abundant.

Conclusions:

• Outdoor PAH emissions significantly contribute to indoor air pollution in preschools.
• Motor vehicle and fuel burning emissions are identified as primary sources.
• Findings highlight the need for strategies to mitigate outdoor PAH infiltration into indoor environments.