Classroom Dust-Bound Polycyclic Aromatic Hydrocarbons in Jeddah Primary Schools, Saudi Arabia: Level, Characteristics and Health Risk Assessment.

Mansour A Alghamdi,Salwa K Hassan,Marwan Y Al Sharif,Mamdouh I Khoder,Noura A Alzahrani

doi:10.3390/ijerph17082779

Abstract

Data concerning polycyclic aromatic hydrocarbons (PAHs) in Jeddah’s schools, Saudi Arabia, and their implications for health risks to children, is scarce. Classroom air conditioner filter dusts were collected from primary schools in urban, suburban and residential areas of Jeddah. This study aimed to assess the characteristics of classroom-dust-bound PAHs and the health risks to children of PAH exposure. Average PAH concentrations were higher in urban schools than suburban and residential schools. Benzo (b)fluoranthene (BbF), benzo(ghi)perylene (BGP), chrysene (CRY) and Dibenz[a,h]anthracene (DBA) at urban and suburban schools and BbF, BGP, fluoranthene (FLT) and indeno (1, 2, 3, −cd)pyrene (IND) at residential schools were the dominant compounds in classroom dust. PAHs with five aromatic rings were the most abundant at all schools. The relative contribution of the individual PAH compounds to total PAH concentrations in the classroom dusts of schools indicate that the study areas do share a common source, vehicle emissions. Based on diagnostic ratios of PAHs, they are emitted from local pyrogenic sources, and traffic is the significant PAH source, with more significant contributions from gasoline-fueled than from diesel cars. Based on benzo[a]pyrene equivalent (BaPequi) calculations, total carcinogenic activity (TCA) for total PAHs represent 21.59% (urban schools), 20.99% (suburban schools), and 18.88% (residential schools) of total PAH concentrations. DBA and BaP were the most dominant compounds contributing to the TCA, suggesting the importance of BaP and DBA as surrogate compounds for PAHs in this schools. Based on incremental lifetime cancer risk (ILCingestion, ILCRinhalation, ILCRdermal) and total lifetime cancer risk (TLCR)) calculations, the order of cancer risk was: urban schools > suburban schools > residential schools. Both ingestion and dermal contact are major contributors to cancer risk. Among PAHs, DBA, BaP, BbF, benzo(a)anthracene (BaA), benzo(k)fluoranthene (BkF), and IND have the highest ILCR values at all schools. LCR and TLCR values at all schools were lower than 10−6, indicating virtual safety. DBA, BaP and BbF were the predominant contributors to cancer effects in all schools.

Highlights

Indoor and outdoor air pollution, both created by human activities and naturally occurring, is considered a serious problem worldwide, since it has been linked with numerous environmental effects and is responsible for increased mortality and morbidity rates [1,2]
Air pollution is responsible for 6.4 million deaths in 2015, which account for 11% of global deaths [3]
The main objectives of this study are: (1) to investigate the concentration levels and profiling of Polycyclic aromatic hydrocarbons (PAHs) in air conditioning (AC) filter dust of some primary schools in Jeddah city that are representative of different environments; (2) to identify the potential sources of the measured

Summary

Introduction

Indoor and outdoor air pollution, both created by human activities and naturally occurring, is considered a serious problem worldwide, since it has been linked with numerous environmental effects and is responsible for increased mortality and morbidity rates [1,2]. Polycyclic aromatic hydrocarbons (PAHs) are long-lived and widely distributed in the environment due to their physicochemical properties, constituted of two or more aromatic rings and formed mainly during pyrolysis and incomplete combustion processes [4,5]. They are distributed in both gaseous and particulate phases in the atmosphere [6,7]. High molecular weight (HMW) PAH compounds, which exist mainly as particulates [8], are not degraded under normal status and their persistence is increased [9]. There is a little information on technologies for PAH removal from the environment [6,10]

Objectives

Methods

Results