Polycyclic aromatic hydrocarbons exposure in residents living near a cement factory with kilns

Elevated exposure to polycyclic aromatic hydrocarbons (PAHs) may trigger cancers in Pakistan: an environmental, occupational, and genetic perspective

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds which are emitted through incomplete combustion of organic materials, fossil fuels, consumption of processed meat, smoked food, and from various industrial activities. High molecular mass and mobility make PAHs widespread and lethal for human health. A cellular system in human detoxifies these toxicants through specialized enzymatic machinery called xenobiotic-metabolizing (CYP450) and phase-II (GSTs) enzymes (XMEs). These metabolizing enzymes include cytochromes P450 family (CYP1, CYP2), glutathione s-transferases, and ALDHs. Gene polymorphisms in XMEs encoding genes can compromise their metabolizing capacity to detoxify ingested carcinogens (PAHs etc.) that may lead to prolong and elevated exposure to ingested toxicants and may consequently lead to cancer. Moreover, PAHs can induce cancer through reprograming XMEs' gene functions by altering their epigenetic markers. This review article discusses possible interplay between individual's gene polymorphism in XMEs' genes, their altered epigenetic markers, and exposure to PAHs in cancer susceptibility in Pakistan.

Increased incidence of respiratory tract cancers in people living near Portland cement plants in Korea

PURPOSE

Portland cement contains carcinogens such as chromium and free silica, and hence, inhalation of cement dust can cause respiratory tract cancers. The purpose of this study was to determine whether living near a cement plant increases the risk of respiratory tract cancers.

METHODS

The study population consisted of 341,793 people, all of whom lived in administrative districts within 3-km radius of ten cement plants in Korea. The respiratory tract cancer incidence data (International Classification of Diseases, ten revision code C00-C14 and C30-C34) for 2008-2012 were obtained from regional cancer registries. Standardized incidence ratios (SIRs) for each cancer site in the respiratory tract were calculated using an indirect standardization method.

RESULTS

Compared with the general Korean population, the incidence of lung and bronchus cancer (C33-C34) was significantly higher in all subjects [SIR 1.15, 95% confidence interval (CI) 1.02-1.29] and especially in the men subjects (SIR 1.47, 95% CI 1.29-1.68) in our study population. In addition, the incidence of larynx cancer in men (SIR 1.64, 95% CI 0.97-2.59) and salivary gland cancer in women (SIR 3.03, 95% CI 0.98-7.07) living near cement plants was marginally increased.

CONCLUSIONS

These results suggest that environmental exposure to Portland cement dust is a risk factor for respiratory tract cancers.

Size-distribution of airborne polycyclic aromatic hydrocarbons and other organic source markers in the surroundings of a cement plant powered with alternative fuels

The distributions of polycyclic aromatic hydrocarbons (PAHs) and molecular tracer organic compounds for biomass combustion, traffic emissions, soil dust, and secondary aerosol processing have been studied in three fractions of ambient air particulate matter (PM10, 2.5, and 1) collected in the vicinity of a cement plant. PAH concentrations were used to estimate the carcinogenic risks in humans. Combustion related compounds, including PAHs, and those from secondary aerosol processing, predominated in the finest (PM<1) fraction, while saccharides related to organic soil dust predominated in the coarse fraction (2.5<PM<10). The molecular markers of biomass combustion were found in high concentrations, indicating the influence of biomass burning on PM. Most predominant PAHs were five and six rings species, related to a PAH profile characteristic of urban-industrial environments. The concentrations of benzo[a]pyrene varied between 0.2 and 1.0ng/m(3), which is close but lower than the annual limit value of 1ng/m(3) established by law. Exposure and inhalation carcinogenic risks from total PAHs were below the EPA threshold of acceptable risk (1·10(-6)).

Spatial Distribution of Polycyclic Aromatic Hydrocarbon (PAH) Concentrations in Soils from Bursa, Turkey

The objectives of this study were to identify regional variations in soil polycyclic aromatic hydrocarbon (PAH) contamination in Bursa, Turkey, and to determine the distributions and sources of various PAH species and their possible sources. Surface soil samples were collected from 20 different locations. The PAH concentrations in soil samples were analyzed using gas chromatography-mass spectrometry (GC-MS). The total PAH concentrations (∑12 PAH) varied spatially between 8 and 4970 ng/g dry matter (DM). The highest concentrations were measured in soils taken from traffic+barbecue+ residential areas (4970 ng/g DM) and areas with cement (4382 ng/g DM) and iron-steel (4000 ng/g DM) factories. In addition, the amounts of ∑7 carcinogenic PAH ranged from 1 to 3684 ng/g DM, and between 5 and 74 % of the total PAHs consisted of such compounds. Overall, 4-ring PAH compounds (Fl, Pyr, BaA and Chr) were dominant in the soil samples, with 29-82 % of the ∑12 PAH consisting of 4-ring PAH compounds. The ∑12 BaPeq values ranged from 0.1 to 381.8 ng/g DM. Following an evaluation of the molecular diagnostic ratios, it was concluded that the PAH pollution in Bursa soil was related to pyrolytic sources; however, the impact of petrogenic sources should not be ignored.