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Commuters are exposed to high air pollution levels daily, especially in areas with dense traffic. This study examines the commuter's exposure to polycyclic aromatic hydrocarbons (PAHs) in the city of Thessaloniki, Greece, under three different commuting modes: biking, travelling by private car, and riding public transportation means (buses). The study was carried out from 2015 to 2018 including 43 volunteers (15 cyclists, 17 car drivers/passengers, and 11 bus passengers). The personal exposure concentrations to particles smaller than 4-μm aerodynamic diameter (PM4), constituting the respirable fraction of total airborne particles, and the associated PAHs were assessed for each commuting mode during the cold and the warm period of the year. Whereas the exposure of bus and car passengers to in-cabin PM4 were higher in the cold season, the exposure of cyclists exhibited the opposite seasonality. In all commuting modes, exposure to PAHs was higher in the cold season. In both seasons, exposure concentration followed the order: cyclists > bus passengers > car passengers. The carcinogenic and mutagenic potencies of the exposure PAH concentrations were calculated using Benzo[a]pyrene (BaP) carcinogenic and mutagenic equivalency factors. The inhalation cancer risk (ICR) associated to PAHs was further estimated and compared between the different commuting modes. Our data can provide relevant information for transport decision-making and increase environmental awareness for a more rational approach to urban travelling. [ABSTRACT FROM AUTHOR]

PM2.1 was collected at urban and suburban elementary schools in Shanghai during two sampling periods in cold and warm seasons in 2007. Nine polycyclic aromatic hydrocarbons (PAHs) and ten nitro-polycyclic aromatic hydrocarbons (NPAHs) in PM2.1 were determined. During both seasons, the concentrations of PAHs and NPAHs at urban and suburban schools were not significantly different (p>0.05) and were higher in the cold period than in the warm period. According to the diagnostic ratios, PAHs and NPAHs at both schools were subject to the mixed effects of vehicle emission and coal combustion during both periods. Moreover, the results of the backward trajectory showed that PAHs and NPAHs were more susceptible to external polluted air masses in the cold period. At both urban and suburban schools, the inhalation cancer risk of PAHs and NPAHs in PM2.1 for children during elementary period was dozens of times of the acceptable risk level regulated by the U.S.EPA, highlighting the adverse impact of exposure to PAHs and NPAHs on the healthy development of children.

In the present study, both gaseous and particulate (PM with dae

Passive air sampling was conducted in Toronto and the Greater Toronto Area from 2016 to 2017 for 6 periods, in order to investigate ambient levels of polycyclic aromatic compounds (PACs) associated with different source types. The selected sampling sites (n = 8) cover geographical areas with varying source emissions including background, traffic, urban, industrial and residential sites. Passive air samples were analyzed for PACs which include PAHs, alkylated PAHs (alk-PAHs), dibenzothiophene and alkylated dibenzothiophenes (DBTs) and results for PAHs were used to calculate inhalation cancer risks using different approaches. The samples were also characterized for PAH derivatives including nitrated PAHs (NPAHs) and oxygenated PAHs (OPAHs). Concentrations of Σalk-PAHs and DBTs, which are known to be enriched in fossil fuels, as well as ΣNPAHs, were highest at a traffic site (MECP) located adjacent to the 18-lane Highway 401 that runs across Toronto. Except for an industrial site (HH/BU), PAC compositions were similar across the sampling sites with Σalk-PAHs being the most abundant class of PACs suggesting traffic emission was a major contributor to PACs in the atmosphere of Toronto. The industrial site exhibited a distinct chemical composition with ΣPAHs dominating over Σalk-PAHs and with elevated levels of fluoranthene, 9-nitroanthracene, and 9,10-anthraquinone, which likely reflects emissions from nearby industrial sources. MECP and HH/BU exhibited higher lifetime excess inhalation cancer risks indicating an association with traffic and industrial sources. The importance of the traffic sector as a source of PACs to ambient air is further supported by strong correlations of the ΣPAHs, Σalk-PAHs, DBTs, and ΣOPAHs with NO x. This study highlights the importance of traffic as an emission source of PACs to urban air and the relevance of PAC classes other than just unsubstituted PAHs that are important but currently not included in air quality guidelines or for assessing inhalation cancer risks. Image 1 • Concentrations were highest at a traffic site located adjacent to a major highway. • Traffic emission was a major contributor to PACs in the atmosphere of Toronto. • The industrial site exhibited a distinct chemical composition. • The traffic and industrial sites exhibited higher inhalation cancer risks. [ABSTRACT FROM AUTHOR]

Lung cancer is the leading cause of cancer occurrence around the world. When exploring the geographic distribution in lung cancer incidence in Poland, we found that PM-bound benzo(a)pyrene (B(a)P) emission from domestic heating contributes to lung cancer risk mostly in areas outside the cities and agglomerations (so-called remaining areas). When averaging B(a)P concentrations within provinces, the B(a)P exposure accounts for even 31% to the total lung cancer cases. To check to which extent the concentration of B(a)P could contribute to an increase probability of lung cancer occurrence, the analysis of health risk was performed. The B(a)P concentration data were downloaded from the Polish Chief Inspectorate of Environmental Protection (CIEP) database. Those concerned the period between 2010 and 2015 and included cities, agglomerations, typically rural sites, and the remaining areas. It was found that the mean concentration of B(a)P in the mentioned period, averaged within specific geographic areas, varied from 1.39 ng/m at the rural sites to 4.86 ng/m in the remaining areas. The inhalation lung cancer risk resulting from the life-long exposure to B(a)P in most conservative (pessimistic) scenario was above the acceptable limits, i.e., E−06. On average, the highest lung cancer risk was found in Opolskie (7.33E−04) and the lowest one in Lubelskie province (1.02E−04), while in the rural areas one order of magnitude lower and amounted to (E−05). Presented results indicate the need for further research on geographic patterns of lung cancer incidence in Poland due to regional differences in air pollution. Such information could be further used for planning long-term strategies to reduce the ambient concentrations of B(a)P. [ABSTRACT FROM AUTHOR]

The main objective of this study was to examine the levels of four heavy metals (As, Cd, Pb and Ni) in PM 10 samples collected in two urban background stations in Dortmund and Bielefeld, in relation to atmospheric circulation. Pollution roses, Conditional Probability Function (CPF) roses and backward air mass trajectory clusters were used to identify air currents associated with the importation of PM 10 and of the included metal constituents. In addition, PM 10 , NO 2 , SO 2 , O 3 , As, Cd, Ni and Pb concentrations were analyzed by a Principal Component Analysis (PCA) to reveal major local emission sources of PM 10 metal content. Traffic was the main emitter of PM 10 , As, Cd, and Pb in both cities, highlighting the existence of non-negligible lead quantities in unleaded gasoline, whilst nickel emissions were associated with heavy fuel oil combustion in industries and primarily for domestic heating. The created CPF roses and trajectory clusters were in good agreement, clearly revealing that eastern air currents enriched the locally produced PM 10 load with additional aerosols from Eastern Europe. The concentrations of arsenic and cadmium were also enhanced by the arrival of air parcels from the East, indicating the anthropogenic origin of the exogenous aerosols due to combustion. The induced cancer risk (CR inh ) for adults, due to inhalation of individual metal constituents, was also estimated in terms of atmospheric circulation, indicating higher risk in Dortmund than in Bielefeld. CR inh values for arsenic exceeded the limit of 1 × 10 −6 in both cities, primarily during the influence of eastern circulation. [ABSTRACT FROM AUTHOR]

To investigate the characteristics of polycyclic aromatic hydrocarbons (PAHs) during haze episodes in warm seasons, daily PM and gaseous samples were collected from March to September 2015 in Hangzhou, China. Daily samples were further divided into four groups by the definition of haze according to visibility and relative humidity (RH), including non-haze (visibility, >10 km), light haze (visibility, 8-10 km, RH <90 %), medium haze (visibility, 5-8 km, RH <90 %), and heavy haze (visibility, <5 km, RH <90 %). Significantly higher concentrations of PM-bound PAHs were found in haze days, but the mean PM-bound PAH concentrations obviously decreased with the aggravation of haze pollution from light to heavy. The gas/particle partitioning coefficients of PAHs decreased from light-haze to heavy-haze episodes, which indicated that PM-bound PAHs were restricted to adhere to the particulate phase with the aggravation of haze pollution. Absorption was considered the main mechanism of gas/particle partitioning of PAHs from gaseous to particulate phase. Analysis of air mass transport indicated that the PM-bound PAH pollution in haze days was largely from regional sources but also significantly affected by long-range air mass transport. The inhalation cancer risk associated with PAHs exceeded the acceptable risk level markedly in both haze and non-haze days. [ABSTRACT FROM AUTHOR]

This study applies a receptor model to quantify source contributions to ambient concentration of polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) and inhalation cancer risk in Taipei from 2003 through 2009. Seventeen PCDD/F congeners were used in the effective variance solution to the Chemical Mass Balance equations to estimate source-specific mass contributions and inhalation risks. The average total PCDD/F concentration was 0.611 pg/Nm 3 (0.036 pg I-TEQ/Nm 3 ). Traffic emissions contributed the most to the PCDD/F concentration (55.7%), followed by waste incinerators (18.6%) and joss stick burning (9.6%). For the inhalation cancer risk, the average was 1.1 × 10 −6 with traffic, waste incinerators, and joss paper burning as the main contributors (67.3%, 19.4%, and 6.3%, respectively). The mass and risk contributions of waste incinerators decreased significantly from 2003 to 2009 and were higher at downwind sites than at upwind sites. Reducing PCDD/F emissions from traffic and waste incinerators would provide the greatest health benefit. Policies that reduce the uncontrolled burning of joss stick and joss paper also need to be implemented. [ABSTRACT FROM AUTHOR]

Thirteen particle-phase PAHs, including nine >4-ring congeners [Benz[a]anthracene (BaAn), Chrysene (Chry), Benzo[b]fluoranthene (BbF), Benzo[k]fluoranthene (BkF), Benzo[e]pyrene (BeP), Benzo[a]pyrene (BaP), Dibenzo[a,h]anthracene (dBaAn), Benzo[g,h,i]perylene (BghiPe), Indeno(1,2,3-c,d)pyrene (IP)], listed by IARC (International Agency for Research on Cancer) as class 1, class 2A, and 2B carcinogens, plus four ≤4-ring congeners [Phenanthrene (Ph), Anthracene (An), Fluoranthene (Fl), Pyrene (Py)], were concurrently measured in inhalable and respirable particle fractions (PM and PM) at a heavy-traffic and an urban background site in Thessaloniki, northern Greece, during the warm and the cold period of the year. Carcinogenic and mutagenic potencies of the PAH-bearing particles were calculated, and the inhalation cancer risk (ICR) for local population was estimated. Finally, Chemical Mass Balance (CMB) modeling was employed for the source apportionment of ambient PAH levels and the estimated lung cancer risk. Resulted inhalation cancer risk during winter was found to be equivalent in the city center and the urban background area suggesting that residential wood burning may offset the benefits from minor traffic emissions. [ABSTRACT FROM AUTHOR]

In the present study, both gaseous and particulate (PM with dae <2.5 µm) phases of polycyclic aromatic hydrocarbons (PAHs) were measured in the ambient air of Hamadan city, Iran. For this reason, two low-volume samplers equipped with glass fiber filters were used for sampling of particulate phase (N = 30) and XAD-2 sorbent tubes were applied for sampling gaseous phase of PAHs (N = 30). The sampling was conducted during warm and cold seasons in 2019. The average of cold/warm season ratios for Σ 16 PAH and PM concentrations were 1.14 and 0.62, respectively. Summed PAHs concentration were determined to be in the range 0.008–59.46 (mean: 11.61) ng/m3 and 0.05–40.83 (mean: 10.22) ng/m3 for the cold and warm seasons, respectively. A negative Pearson correlation coefficient was obtained for wind speed and relative humidity. The average Benzo (a) Pyrene equivalent carcinogenic (BaP eq) levels in the cold season were lower than the maximum permissible risk level of 1 ng/m3 for BaP. The BaP toxicity equivalency (ΣBaP TEQ) and BaP mutagenicity equivalency (ΣBaP MEQ) appeared to be significantly higher in the cold season (averaging 0.35 and 1.65 ng/m3, respectively) than those in warm season. Health risk assessment was performed for children and adults based on BaP eq , inhalation cancer risk. The diagnostic ratios of individual PAHs concentration showed that the significant sources of PAH emissions may be related to light duty vehicles (LDVs) in Hamadan. Although, some other sources such as pyrogenic source and petrol combustion were also suggested. ga1 • Mean PM 2.5 concentrations were measured in the ranges of 1.33–30.82 μg/m3. • Σ16 PAHs concentration were predominant in the cold season and gas phase. • Risk assessment based on ΣBaPTEQ and ΣBaPMEQ shows low potential carcinogenic risks. • Two and three-rings PAHs (LMWs) were the dominant contributors to local PAHs. • Pyrogenic sources and light duty vehicles were recognized as the main sources of PAHs. [ABSTRACT FROM AUTHOR]

• PM 10 -bound metals, cancer and non-cancer risk assessment for the subway commuter. • Inhalation cancer risks levels are compared incremental lifetime cancer risk. • For adults, cancer risk were found higher than the acceptable limit (>1 × 10−5). • Cr(VI) showed the highest contribution to the cancer risk levels with 91%. Non-cancer and cancer health risks to humans associated with respirable particulate matter ≤10 µm (PM 10) in an indoor microenvironment such as a subway cabin are currently a public concern. In this study, detailed investigations of human health risks due to PM 10 -bound metals in a subway cabin were conducted for the first time. Cancer risks (CRs) were estimated for inhalation exposure (CR inh) using a Monte Carlo probability density function and were compared with incremental lifetime CRs (ILCRs). Moreover, the percentage contributions of each metal to the risk levels were calculated to identify the elements potentially responsible for human health risks. The significant (>1) for non-CRs levels as HI (hazard index) was estimated for children and adults for all types of exposure (inhalation, ingestion, and dermal). Pb, Cr, and Ni were recognized as the foremost contributors to the HQ (hazard quotient) levels for all types of exposure. For subway commuters, the CR inh and ILCR levels for adults were marginally higher than the satisfactory maximum point of confinement of the lifetime carcinogenic risk level (1 × 10−5) where as CR inh for children was within the acceptable limit (1 × 10−6–1 × 10−5). Cr was identified as the predominant carcinogenic element, with 91% contribution to the total CR level in the subway cabin on the Seoul Metropolitan Subway. [ABSTRACT FROM AUTHOR]

There are few ambient air measurements of extended lists of carcinogenic polycyclic aromatic hydrocarbons (cPAHs); which are pollutants useful in source identification and significant contributors to cumulative inhalation cancer potency. We present findings from a multi-year ambient air sampling study with comparisons of cancer risk estimates for monitoring sites influenced by a variety of sources based on Minnesota Department of Health guidance. Cancer risks were calculated from raw cPAH measurements and cPAH measurements adjusted by wind direction to reflect the full potential impact of the facility's air emissions. MDH cPAH Guidance was used to calculate additive cancer risks for all cPAHs analyzed in this study, as well as the following priority cPAH groups: the EPA16, the EU15 + 1, the EU7 (ambient air), a scaling to Benzo[a]pyrene, and the polycyclic aromatic hydrocarbons (PAHs) categorized by IARC as carcinogenic. The highest cPAH risks were from the urban mixed source site. Benzo[c]fluorene was the highest contributor to the cumulative inhalation risk. Adjusting cPAH concentrations by wind direction to reflect full source emissions had a large impact on data for the traffic site and the refineries, but less to no difference for the shingle manufacturing sites. If not all cPAHs are analyzed in a monitoring study, the risk estimates from the EU15 + 1 priority PAHs was the closest surrogate to a full suite of cPAHs followed by the use of a multiplier times a surrogate PAH. • Wind direction adjustments had the largest impact on traffic and refinery sites. • Benzo[c]fluorene (BcF) was the highest contributor to the cumulative inhalation risk. • The EU15 + 1 priority PAH list was the closest surrogate to a full suite of cPAHs. • Chrysene can be used as a surrogate for total inhalation cPAH risk estimation. [ABSTRACT FROM AUTHOR]