a b s t r a c tConcentrations of volatile organic compounds (VOCs), including formaldehyde, in classrooms, kindergartens, and outdoor playgrounds of three primary schools were measured in spring, winter, and fall terms inİzmir, Turkey. A health-risk assessment was conducted for odor detection, sensory irritation, chronic toxic effects, and cancer. Active sampling was applied for VOCs and formaldehyde on Tenax TA and DNPH tubes, respectively. VOCs were analyzed in a thermal desorption-GC-MS system. Formaldehyde analysis was performed using an HPLC instrument. Benzene, toluene, and formaldehyde were the most abundant compounds with 95th percentile indoor air concentrations of 29, 87, and 106 g/m 3 , respectively. Naphthalene and xylenes followed them with an order of magnitude lower concentrations. Two isomers of dichlorobenzene (1,3 and 1,4) were the other notable compounds. The concentrations were utilized to classify the indoor air pollutants with respect to potential health effects. In addition, carcinogenic and chronic toxic risks were estimated using Monte-Carlo simulation. Formaldehyde appears to be the most concerning pollutant with high chronic toxic and carcinogenic risk levels according to the health assessment followed by naphthalene, benzene, and toluene due to their chronic effects.
The micro-structure of laminar premixed, atmospheric-pressure, fuel-rich flames of n-heptane/oxygen/argon has been studied at two equivalence ratios (C/O ϭ 0.63 and C/O ϭ 0.67). A heated quartz microprobe coupled to an online gas chromatography/mass spectrometry (HP 5890 Series II/HP 5972) has been used to establish the identities and absolute concentrations of stable major, minor, and trace species by the direct analysis of samples withdrawn from the flames. Benzene was the most abundant aromatic compound identified. The largest PAH detected were the family of C 18 H 10 (molecular weight of 226) that include cyclopenta[cd]pyrene and benzo[ghi]fluoranthene, with peak concentrations reaching 8 ppm and 6 ppm, respectively. Soot particle diameters, number densities, and volume fractions were determined using classical light scattering and extinction measurements. The largest soot particle diameter measured was about 18 nm and the soot volume fraction reached the amount of 4.9 ϫ 10
Ϫ7.
Effects of three oxygenate additives (methanol, ethanol, and MTBE) on the formation of polycyclic aromatic hydrocarbons (PAHs) and soot in laminar, premixed, atmospheric pressure, fuel-rich flames of n-heptane were studied at an equivalence ratio of 2.10. A heated quartz microprobe coupled to online gas chromatography=mass spectrometry was used to establish the identities and absolute concentrations of major, minor, and trace species by the direct analysis of samples withdrawn from the flames. Benzene was the most abundant aromatic compound identified. The largest PAH detected was the family of C 18 H 10 (molecular weight of 226) that includes cyclopenta[cd]pyrene and benzo[ghi]fluoranthene. Soot particle diameters, number densities, and volume fractions were determined using classical light scattering and extinction measurements. All the oxygenate additives studied reduced the mole fractions of aromatic and PAH species, as well as soot formation. However, the reduction in soot formation was comparable for different oxygenates under the experimental conditions investigated.
Exposure
Risk Trihalomethanes
İzmir
A B S T R A C TConcentrations of volatile organic compounds (VOCs) were measured in the drinking water in Province of İzmir, Turkey, and associated health risks due to ingestion of these compounds were investigated using population weighted random samples. A total of 100 houses were visited in different districts of İzmir and drinking water samples were collected from consumers' drinking water source. Questionnaires were administered to one participant in each house to determine demographics and drinking water consumption rates. Oral exposure and risks were estimated for each participant and İzmir population by deterministic and probabilistic approaches, respectively. The four trihalomethane (THM) species (i.e., chloroform, bromodichloromethane, dibromochloromethane, and bromoform), benzene, toluene, p-xylene, and naphthalene were the most frequently detected VOCs with concentrations ranging from below detection limit to 35 mg/l. The risk estimates were found to be less than the values reported in the literature with few exceptions.Noncarcinogenic risks attributable to ingestion of VOCs for İzmir population were negligible, whereas the mean carcinogenic risk estimates for bromodichloromethane and dibromochloromethane were above the de minimis level of one in a million (10 À6 ). For all VOCs, the concentrations measured in metropolitan area were greater than those in other districts. All THM species were detected in higher concentrations in tap water, whereas nontap water contained more benzene, toluene, p-xylene, and naphthalene. Therefore, the concentrations of the latter four compounds and associated risks increased with increasing income and education level since bottled water was used in larger proportions within these subgroups. The results of this study showed that oral exposure to drinking water contaminants and associated risks may be higher than the acceptable levels even if the concentrations fall below the standards.
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