Assessment of incremental lifetime cancer risks of ambient air PM10-bound PAHs in oil-rich cities of Iran

This study investigates the concentrations of PM₁₀-bound PAHs and their seasonal variations in three cities of Ahvaz, Abadan, and Asaluyeh in Iran. The mean concentrations of PM₁₀ in two warm and cold seasons in Ahvaz were higher and in Abadan and Assaluyeh were lower than the national standard of Iran and the guidelines of the World Health Organization. The Σ16 PAHs concentration in ambient air PM₁₀ during the cold season in Ahvaz, Abadan and Asaluyeh was 244.6, 633, and 909 ng m^- 3, respectively, and during the warm season in Ahvaz, Abadan, and Asaluyeh was 242.1, 1570 and 251 ng m^- 3, respectively. The high molecular weight PAHs were the most predominant components. The most abundant PAHs species were Pyr, Chr, B [ghi] P, and Flt. The results showed that the total PAHs concentration in the cold and warm seasons was dependent on industrial activities, particularly the neighboring petrochemical units of the city, vehicular exhausts, traffic and use of oil, gas, and coal in energy production. The total cancer risk values as a result of exposure to PAHs in ambient air PM₁₀ in all three cities for children and adults and in both cold and warm seasons were between 1 × 10^- 6 and 1 × 10^- 4, and this indicates a potential carcinogenic risk. Therefore, considering the various sources of air pollutants and its role on people's health, decision makers should adopt appropriate policies on air quality to reduce the ambient air PAHs and to mitigate human exposure.

Polycyclic aromatic hydrocarbons in PM1, PM2.5 and PM10 atmospheric particles: identification, sources, temporal and spatial variations

This study reports temporal and spatial variations of 16 different species of particulate polycyclic aromatic hydrocarbons (particle-bonded PAHs) in the indoor and outdoor environments of three sampling sites in Bandar Mahshahr city, Iran. A low-volume air sampler was employed to collect size-segregated particulate matter during winter (October to December 2015), and summer (July to September 2016). The results showed that the annual concentrations of indoor and outdoor PM10 and PM2.5 were much higher than the related World Health Organization guidelines. The concentration of total particle-bonded PAHs (TPAHs) was higher in winter than in summer and a significant difference between the two sampling seasons was observed. The indoor and outdoor carcinogenic PAHs to TPAHs concentrations ratios in the sampling sites in summer and winter were as follow: for PM10 40.15-42.51%, PM2.5 41.30-42.97%, and PM1 43.07-44.36%, respectively; furthermore, the smaller the particle size, the higher the percentage of carcinogenic PAHs. 2 ring PAHs had a very small contribution to the total PAHs (about 1%), whereas PAHs with 3-to-4 rings had much larger contributions, ranging from 71.65% to 75.17%. The results demonstrated that as PM size decreased, the proportion of 5-to-6-ring PAHs to the total PAHs increased. Since 5-to-6- ring PAHs are considered to be more toxic, hence more attention should be paid to fine particles. The diagnostic ratios of indoor and outdoor of three sampling sites in both seasons suggested that petrogenic sources, as well as combustion of petroleum and other fossil fuels were the main PAHs sources.

Health risk assessment of exposure to the Middle-Eastern Dust storms in the Iranian megacity of Kermanshah

OBJECTIVE

This study assessed the effects of particulate matter (PM), equal or less than 10 μm in aerodynamic diameter (PM₁₀), from the Middle-Eastern Dust events on public health in the megacity of Kermanshah (Iran).

STUDY DESIGN

This study used epidemiological modeling and monitored ambient air quality data to estimate the potential PM₁₀ impacts on public health.

METHODS

The AirQ2.2.3 model was used to calculate mortality and morbidity attributed to PM₁₀ as representative of dust events. Using Visual Basic for Applications, the programming language of Excel software, hourly PM₁₀ concentrations obtained from the local agency were processed to prepare input files for the AirQ2.2.3 model.

RESULTS

Using baseline incidence, defined by the World Health Organization, the number of estimated excess cases for respiratory mortality, hospital admissions for chronic obstructive pulmonary disease, for respiratory diseases, and for cardiovascular diseases were 37, 39, 476, and 184 persons, respectively, from 21st March, 2014 to 20th March, 2015. Furthermore, 92% of mortality and morbidity cases occurred in days with PM₁₀ concentrations lower than 150 μg/m³. The highest percentage of person-days occurred for daily concentrations range of 100-109 μg/m³, causing the maximum health end-points among the citizens of Kermanshah.

CONCLUSIONS

Calculating the number of cumulative excess cases for mortality or morbidity attributed to PM₁₀ provides a good tool for decision and policy-makers in the field of health care to compensate their shortcomings particularly at hospital and healthcare centers for combating dust storms. To diminish these effects, several immediate actions should be managed in the governmental scale to control dust such as spreading mulch and planting new species that are compatible to arid area.