# Determination of Polycyclic Aromatic Hydrocarbons and Organic Molecular Tracer Compounds in Dusts Samples from Schools in Puchuncaví and Quintero (Chile)

## TL;DR

This study measured harmful chemicals in dust from schools in Chile to identify sources and health risks for children.

## Contribution

The study identifies three pollution sources and quantifies cancer risks from PAH exposure in schools in Chile.

## Key findings

- Incomplete combustion processes contributed 46.38% of PAHs in dust samples.
- Benzo[a]pyrene was the main contributor to PAH toxicity in schools in Puchuncaví.
- Dust ingestion posed the highest cancer risk, with ILCR values ranging from 1.14 × 10−3 to 8.88 × 10−4.

## Abstract

This investigation was conducted in order to gain a first knowledge of concentrations, distribution patterns, and potential sources of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) and organic molecular tracer compounds in deposition dust samples collected in the Valparaiso region, Chile. Dust was sampled in schools (indoor and outdoor) that are located in Puchuncaví and Quintero. Source apportionment analysis using the concentrations of PAHs; glucose, mannitol, sucrose, fructose; di-2-ethylhexyl phthalate; hopanes, and levoglucosan as molecular tracer compounds showed three sources of contribution. The first (46.38%) was related to incomplete combustion processes (Acy, Flu, Ant, Flt, Pyr, and BaA), a second source (20%) represented soil+ biomass burning (levoglucosan, α glucose, β glucose, mannitol, sucrose, and fructose), and a third source (10.26%) was dominated only by 27_norhopane, 27_hopane, which are related to traffic. To assess potential health risks for schoolchildren, the study calculated the benzo[a]pyrene equivalent (BaPE) toxicity and the incremental lifetime cancer risk (ILCR). Toxicity equivalent (TEQ) results showed that the main contributor to overall toxicity in PAHs, especially in schools located in Puchuncaví, was benzo[a]pyrene (BaP), followed by benzo[α]anthracene (BaA), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), indeno[1,2,3-cd] pyrene (IcdP), and dibenzo[a,h]anthracene (DahA). According to the calculated ILCR values, the highest cancer risk was associated with dust ingestion (both indoor and outdoor) for ∑16PAHs, ranging from 1.14 × 10−3 to 8.88 × 10−4. This was followed by dermal contact (1.27 × 10−5 to 7.27 × 10−7) and inhalation (1.22 × 10−8 to 9.99 × 10−9).