صادق نیازی

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic pollutants that are mostly generated during the incomplete combustion. The main objective of this study was to characterize potential sources of PAHs in Tehran.
Samples of PM10 were collected at 10 monitoring stations belonging to Tehran Air Quality Control Company (AQCC) and transferred to laboratory for analysis. Besides, a SKC Flite 2 Air Sampling Pump (SKC, USA) equipped with a sampling head and PM10 size-selective inlet was used at four stations to compare the results obtained by collecting AQCC monitors (AQCCMs) tapes with the standard sampling procedures for assessing the interchangeability of two field sampling methods. The principal component analysis (PCA) and diagnostic ratios were applied to identify emission sources and source contribution.
The average diagnostic ratios of phenanthrene (Phe)/ (Phe橻憭ꜞ (Ant)), benzo(a)anthracene (BaA)/ (BaA爚 (Chry)), fluorantene(Flu)/ (FluꜪ� (Py)), and indeno(1,2,3cd) pyrene (IcP)/(IcP淩(ghi)perylene (BghiP)) in samples were 0.79, 0.52, 0.43 and 0.38, respectively. These ratios showed that the combustion, especially fossil fuels and motor vehicles, was the main sources of PAHs emission in Tehran. The results of PCA analysis also indicated that 49, 29 and 22% of PAHs sources in Tehran atmosphere were attributed to gasoline-driven vehicles, diesel vehicles and other sources, respectively.
According to the results, the combustion, especially fossil fuel and motor vehicle, was the main sources of PAHs emission in Tehran.

Air pollution in major cities is one of the most important concerns of the society. BTEX compounds; benzene, toluene, ethyl benzene, and xylenes are categorized as monocyclic aromatic chemicals. MTBE, ETBE and TAME are oxygenated compounds belonging to the class of ethers. All of these compounds are mainly added to gasoline to enhance octane rate, reduce carbon monoxide emission and improve combustion process as an alternatives to alkyl-lead compounds. The aim of this study was to determine concentrations of urinary biomarkers of mentioned chemicals in subjects with no occupational exposure history. This is a cross-sectional study conducted in 2013. Spot urine samples were collected from 30 healthy volunteers (18 from indoor and 12 from outdoor environments). Head space solid phase micro extraction (HS-SPME) technique was used to extract compounds and a gas chromatograph equipped with FID detector for sample analysis. The mean concentrations of urinary biomarkers of benzene, toluene, ethyl benzene, p+m-xylene, o-xylene, MTBE, ETBE, TAME were respectively 81, 87, 31, 198, 44, 184, 31 and 0 ng/L. No significant difference (p>0.05) was observed in concentrations of urine biomarkers between two groups. According to the results of this and other studies, biomarkers are useful criteria for assessing human exposure to environmental pollutants.

Giardiasis is one of the parasitic infections in the gastrointestinal tract which caused by flagellate protozoa that called giardia and it causes diarrhea. Giardia cysts defecate from infected people. These cysts can enter the body through contaminated hands, water, and food products. Diarrhea, weight loss, abdominal pains, growth failure, malabsorption of carbohydrates, fats and vitamins are the giardiasis symptoms. In this study, samples were taken from 203 people that were working in different food supply and distribution centers in the South Pars petrochemical. After sampling, samples were analyzed according to standard procedures. The results of examinations were studied after verification them by laboratory chief and their related physicians. Out of the whole examined people in this study, kitchen (28%) and salad maker (14%) centers were the maximum and minimum population, respectively. 8.87% of the total populations were infected by giardia, which salad making center had the greatest share. As well as, the rate of infectious by giardia among the administrative and dishes washing centers was the lowest. Education level and personal hygiene such as hand washing with a detergent can be important in reducing infection due to giardia. So, the training of workers and also periodic testing of individuals can reduce these pollutants.