This study aims to investigate the air quality in primary school placed in district of Taranto (south of Italy), an area of high environmental risk because of closeness between large industrial complex and urban settlement. The chemical characterization of PM2.5 was performed to identify origin of pollutants detected inside school and the comparison between indoor and outdoor levels of PAHs and metals allowed evaluating intrusion of outdoor pollutants or the existence of specific indoor sources. The results showed that the indoor and outdoor levels of PM2.5, BaP, Cd, Ni, As, and Pb never exceeded the target values issued by World Health Organization (WHO). Nevertheless, high metals and PAHs concentrations were detected especially when school were downwind to the steel plant. The
Children spend most of day in indoor environments and especially in school classrooms [
Airborne particles in classroom have been recognized as the principal class of contaminants that can affect indoor air quality and students health [
Until now, only few studies have characterized the chemical composition of indoor particles and little is known regarding the school environment [
The aim of the present study is to characterize IAQ in a primary school building located nearby the high-impact industrial sites such as the industrial area of Taranto (south of Italy).
The industrial area of Taranto is, in fact, considered one of the areas of high environmental risk and it is included in the list of polluted sites of national interest because of the presence of a large industrial complex near the urban settlement.
PM2.5 samples were collected inside the atrium of the school building located in a district of Taranto city, called Tamburi, few kilometres away from the biggest European steel plant. Taranto (40°28′N 17°14′E) is the third most populated city of the Southern Italy and its industrial area includes the biggest steel plant in Europe, a refinery, a quarry, a cement plant, a composting plant, and military and trade harbors. Because of the proximity of this large industrial complex to the urban settlement (Tamburi district), Taranto is one of the areas identified at high environmental risk in Italy and it has been included in the list of the polluted sites of national interest (Figure
Map of Taranto (south of Italy). Red star shows sampling site.
Eleven daily samples of PM2.5 were collected from 11 to 22 December 2014 on quartz fiber filters (Whatman) using low-volume air sampler (Skypost by TRC TECORA) and FAI sampling heads operating to 2.3 m3 h−1. According to UNI EN 1234-1, the collected PM filters were conditioned for 48 hours in a climatic chamber provided with a control system for the temperature and the humidity (
Then, the PM filters (47 mm diameter) were cut in two parts: half of the filter was analysed in order to determinate elements (Al, V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) and the other half was analysed for PAHs determination (Benzo[a]anthracene (BaA), benzo[b+j]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene (IP), benzo[ghi]perylene (BgP), and dibenzo[a,h]anthracene (DBA)).
Simultaneously, real-time monitoring of total PAHs was carried out by means Ecochem PAS monitor (Saras S.p.A.) in order to study the activation of sources during the monitored days. This monitor, using an Excimer lamp at a determined wavelength, ionizes only the carbon aerosols, while gas molecules and noncarbon aerosols remain neutral. The positively charged particles are collected on a filter inside an electrometer, where the charge measured is proportional to the concentration of total PAH. Indoor/outdoor (
Half of PM2.5 filters were extracted with a mixture of acetone/hexane by means of a microwave assisted solvent extraction (Milestone, model Ethos D). The extracted samples were analysed using an Agilent 6890 PLUS gas chromatograph (Agilent Technologies, Inc., Santa Clara, CA, USA) equipped with a programmable temperature vaporization injection system (PTV) and interfaced to a mass spectrometer, operating in electron impact ionization (Agilent MS-5973 N). Benzo[a]anthracene (BaA), benzo[b+j]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene (IP), benzo[ghi]perylene (BgP), and dibenzo[a,h]anthracene (DBA) were determined using the signals corresponding to the molecular ions: BaA (228), BbF (252), BkF (252), BaP (252), IP (276), BgP (276), and DbA (278). Perylene-D12 (PrD, 264) was used as internal standard (IS). The analytical performances (extraction recovery, extraction linearity, analytical repeatability, and LOD) were verified in our previous work [
In addition, the other half of PM2.5 samples were digested in 8 ml of nitric acid and 2 ml of hydrogen peroxide solution by using a microwave system (Milestone mod. Ethos D). The extract was analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS, Perkin Elmer NexION 350) in order to determine Al, V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb using Rh as internal standard. Recoveries varied from
The basic statistics (mean, maximum, and minimum) of mass and chemical composition of PM2.5 determined for the investigated period and school are summarized in Table
Mean, minimum, and maximum concentration of PM2.5 (
Mean |
This study | Viana et al., 2014 [ |
Zwoździak et al., 2013 [ |
Hassanvand et al., 2015 [ |
Oliveira et al., 2017 [ |
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Location | Taranto, Italy | Barcelona, Spain | Wroclaw, Poland | Tehran, Iran | Oporto, Portugal |
|
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BaA | 0.15 (0.11–0.23) | 24.5 | 0.046 (0.041–0.051) | ||
Cr | 0.21 (0.17–0.28) | 39.26 | 0.13 (0.11–0.15) | ||
BbF | 0.51 (0.33–0.71) | 23.75 | 0.7 (0.59–0.83) | ||
BkF | 0.29 (0.20–0.39) | 12.22 | 0.12 (0.10–0.15) | ||
BaP | 0.22 (0.14–0.32) | 5.42 | 0.27 (0.21–0.33) | ||
IP | 0.34 (0.24–0.52) | 2.23 | 0.44 (0.36–0.52) | ||
DBA | 0.25 (0.18–0.34) | 13.75 | 1.5 (1.3–1.8) | ||
BgP | 0.42 (0.24–0.68) | 10.43 | 0.61 (0.51–0.74) | ||
Al | 635.3 (521.8–703.2) | 561 | 39.72 | ||
V | 1.17 (0.81–1.92) | 3.4 | |||
Cr | 14.5 (11.9–19.6) | 3.1 | 6.06 | 5.55 | |
Fe | 212 (93.9–693) | 200 | 525 | 102.20 | |
Mn | 4.93 (2.36–8.58) | 5.9 | 46 | 15.25 | |
Co | 0.18 (0.13–0.25) | ||||
Ni | 5.24 (3.20–10.6) | 2.3 | 2.04 | 4.66 | |
Cu | 13.9 (6.7–26.8) | 9.1 | 50 | 22.17 | |
Zn | 15.5 (5.20–30.5) | 42.1 | 267 | 68.90 | |
As | 0.64 (0.42–0.81) | 0.34 | 4 | 3.01 | |
Cd | 0.09 (0.05–0.15) | 0.69 | 0.29 | ||
Pb | 3.81 (1.65–10.6) | 3.73 | 85 | 60.60 | |
PM2.5 |
16.6 (10.6–27.1) | 29.9 | 59.8 (18.2–86.6) | 20 (3–81) | 25.8 (9.2–66.6) |
During the investigated period, no significant differences can be observed for PM2.5 concentrations determined inside and outside the school. The mean PM2.5 concentrations were 16.6 and 15.9
The mean
Scatterplot showing the indoor/outdoor correlation for PM2.5.
The mean levels of metals measured in indoor PM2.5 samples during sampling campaign are summarized in Table
The concentrations of Pb determined in this study were comparable to those measured in Spain [
In addition to lead, also Ni, Cd, and As, classified by the IARC as carcinogenic to humans (Group 1), never exceeded standard annual outdoor levels (20, 6, and 5 ng/m3, resp.) settled by European Commission (EC) [
Although V concentrations resulted lower than those measured in Spanish schools [
Finally, Cr levels resulted up to 5 times greater than those obtained in other works (Table
Among individual PAHs bound to PM, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]luoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, and indeno[1,2,3-cd]pyrene were designated by International Agency Research on Cancer as possible or probable carcinogens (IARC, 2002, 2010) and were analysed in this work. The levels of these carcinogenic PAHs (i.e., ΣPAHs) at the indoor air of the studied school ranged from 1.51 and 2.36 ng/m3 accounting for 14.3% of PM2.5 concentration. The indoor concentrations of the eight carcinogenic PAHs, that is, BaA, Chr, BbF, BkF, BaP, BgP, DBA, and IP, were similar to those found in a primary school of Portugal [
As concerns benzo[a]pyrene, indicator of carcinogenic PAHs, the current European legislation on ambient air (Directive 2004/107/EC, 2005) sets annual target value of 1 ng m−3 for carcinogenic PAHs in PM10. The mean concentration of this pollutant during the sampling period was
One of the most important aspects of the air quality management process is the identification of the source of pollutants. Indoor-to-outdoor (
Trend of real-time PAHs concentrations monitored inside and outside the investigated school.
In addition, analysis of diagnostic ratios of individual PAH congeners can provide further insight regarding PAHs origin. In fact, because of different sources show specific concentration profiles of PAHs, several studies focused on PAHs diagnostic ratios, especially on B(a)P/B(g)P and IP/(IP + BgP) ratios [
DRs range determined in literature and in this study.
BaP/Chry | B(a)P/B(g)P | IP/(IP + BgP) | BaA/(BaA + Chry) | |
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|
0.5–0.6 |
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Diesel emissions | 0.45–0.83 | |||
Gasoline cars | 0.30–0.40 | 0.21–0.22 [ |
0.76 [ | |
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|
0.45 |
0.36 |
||
|
||||
|
>0.35 [ |
≥1.25 [ |
0.33 |
|
|
0.9–6.6 [ |
0.56 |
0.27–0.65 [ | |
|
|
0.43 [ | ||
|
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|
1.06 |
0.64 |
0.45 |
0.41 |
|
0.77 |
0.47 |
The main goal of this work was to assess the impact of the biggest European steel plant on nearby residential area of Taranto (South of Italy) and, in particular, on indoor air quality inside school. Therefore, a PM2.5 sampling campaign was carried out from December 11 to 22, 2014, in a primary school located in Tamburi district of Taranto. The chemical characterization of PM provided PAH and metal concentrations. In addition, real-time total PAHs were monitored inside and outside the investigated school. The results showed that the indoor and outdoor levels of PM2.5, BaP, Cd, Ni, As, and Pb were lower than guidelines issued by World Health Organization (WHO). Nevertheless, high metals and PAHs concentrations were detected especially when schools were downwind to the steel plant. The
This manuscript is based on a paper presented to TECH-AIR 2016 conference.
The authors declare that there are no conflicts of interest regarding the publication of this paper.
Special appreciation goes to ARPA Puglia, especially to Dr. Dambruoso Paolo Rosario and Dr. Placentino Claudia Marcella for the collaboration in sampling campaign.