Ertan Durmusoglu

Health risk assessment of BTEX emissions in the landfill environment.

This study focuses on a health risk assessment related to benzene, toluene, ethylbenzene, and m,p,o-xylene (xylenes) (BTEX) exposure via inhalation for workers at a landfill (LF) site. First, the landfill gas (LFG) samples were collected and analyzed accordance with US EPA method TO-17. The mean concentrations of benzene, toluene, ethylbenzene, and xylenes were determined as 140.3, 1271.7, 239.9, and 341.3 microg/m(3), respectively. Then, a risk assessment methodology was employed to evaluate the potential adverse health effects of the individual BTEX compounds according to their carcinogenicities. The corresponding mean cancer risk for benzene was estimated to be 6.75E-05 that is lower than the designated acceptable risk level of 1.0E-04. With respect to mean non-carcinogenic risks for toluene, ethylbenzene, and xylenes, both individually and cumulatively, they were lower than the specified level of 1.0. These findings reveal that landfill BTEX emissions do not pose a health threat to workers at the landfill site. In addition, as far as the risks are concerned for the population in the neighborhood area of the landfill, air dilution of BTEX emitted from LF site is widely sufficient to guarantee their protection.

The prevalence of molar incisor hypomineralization (MIH) in a group of children in a highly polluted urban region and a windfarm-green energy island

BACKGROUND Childrens developing teeth may be sensitive to environmental pollutants such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans. The term molar incisor hypomineralization (MIH) was introduced to describe the clinical appearance of enamel hypomineralization of systemic origin affecting one or more permanent first molars (PFMs) that are associated frequently with affected incisors. AIM The aim of this study was to determine the prevalance of MIH in children from the most industrialized and polluted region and the most green-energy island of Turkey. DESIGN In September 2007, a retrospective study was initiated in two elementary schools: one, a group of children (N = 153) who fitted the criteria from Tavsancil, Kocaeli (N = 109) and the other from Bozcaada island, Canakkale (N = 44). The soil samples were collected from selected regions in order to determine the contamination levels in a heavily industrialized area and a non-industrialized area. RESULTS Prevalance of MIH in children in Bozcaada island was 9.1%, while prevalance of MIH was 9.2% in Tavsancil. The PCDD/F levels in soil samples collected from Bozcaada and Tavsancil were determined as 1,12 and 8,4 I-TEQ ng/kg dry soil, respectively (P < 0.001). CONCLUSIONS In this preliminary study with a small study population, prevalence of MIH did not seem to be associated with the levels of PCDD/Fs in the environment.

Levels of PCDD/Fs in local and non-local food samples collected from a highly polluted area in Turkey

A sampling and analysis program were conducted to determine the PCDD/F levels in various food samples collected in Kocaeli, one of the highly polluted areas in Turkey. Several food samples including animal (egg, chicken, meat and cows milk) and plant (fruits, leafy vegetables, fruiting vegetables, rooty vegetables and flour) products were collected from both local and non-local (commercial) sources. The local food samples were taken from 20 sampling points selected by taking into account the location of the possible PCDD/F sources, dominant wind directions and representing the major part of the Turkish daily diet The PCDD/F concentrations in local eggs and milk samples were ranged from <1.16 to 10.94 pg TEQ g(-1) fat and from <0.43 to 3.29 pg TEQ g(-1) fat, respectively. On the other hand, the PCDD/F concentrations were measured between 0.28-1.81 pg EQ g(-1) fat in local meat samples and 0.15-2.92 pg TEQ g(-1) fat in local chicken samples. The PCDD/F concentrations in the plant products were relatively low and most of the congeners were measured below the detection limits except for the leafy vegetables. In addition, several commercial samples were analyzed in order to evaluate the differences of PCDD/F levels in samples collected from both the local and non-local sources. The results showed that the local animal products have higher PCDD/F concentrations than the non-local ones. Moreover, the commercial plant products showed undetectable concentrations for most of the congeners. Finally, the PCDD/F levels in some animal products were found to be higher than the national limit values.

Temporal variation of decomposition gases from baled municipal solid wastes

In this study, after nine cylindrical bales containing a mix of different waste materials were constructed, they were stored in the open air and temporal variations of CO(2), CH(4), O(2), and N(2) were monitored over 10 months. In each bale, different waste fractions were considered in order to represent different moisture contents. The results showed that CO(2) increased within very few days to approximately 80% and stabilized later in the range of between 10% and 35% in a month. The O(2) levels dropped from approximately 15% to significantly less than 1%. There was no significant anaerobic decomposition since CH(4) did not exceed 5% during the whole test period. N(2) exhibited an opposite pattern with CO(2). In addition, relationships between waste species in the bales and gas formations were determined by a bivariate correlation analysis. An empirical prediction model for the maximum CO(2) production was also developed.

Health risk assessment of background PCDD/F exposure levels in Kocaeli, Turkey.

An estimation and assessment of the polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo furans (PCDD/Fs) exposure levels for the people living in Kocaeli, the most industrialized area of Turkey, are presented. The information is based on the results of PCDD/F analyses in the samples collected from various environmental media and the multimedia exposure assessment methodology. Exposure scenarios were constructed on a site-specific basis by combining the exposure pathways appropriate to the area, and the activity patterns of the people living in Kocaeli. The model showed that the exposure levels of PCDD/Fs were in the range of 3.7–13.1 pg I-TEQ.kg− 1 bw for adult receptors, which are higher than the recommended TDI value of 2 pg TEQ.kg− 1 bw. The PCDD/F intakes for rural receptors were estimated to be three times higher than those for urban and semi-urban receptors due mainly to the consumption of locally grown foods. The assessment of the contributions of various exposure pathways to the total exposure and the sensitivity analysis performed based on a probabilistic approach indicated that PCDD/F intakes for adult receptors are directly proportional to the locally grown fraction of plant groups consumed.

Energy content of municipal solid waste bales

Baling technology is a preferred method for temporary storage of municipal solid waste (MSW) prior to final disposal. If incineration is intended for final disposal of the bales, the energy content of the baled MSW gains importance. In this study, nine cylindrical bales containing a mix of different waste materials were constructed and several parameters, including total carbon (TC), total organic carbon (TOC), total Kjeldahl nitrogen, moisture content, loss on ignition, gross calorific value and net calorific value (NCV) were determined before the baling and at the end of 10 months of storage. In addition, the relationships between the waste materials and the energy contents of the bales were investigated by the bivariate correlation analyses. At the end, linear regression models were developed in order to forecast the decrease of energy content during storage. While the NCVs of the waste materials before the baling ranged between 6.2 and 23.7 MJ kg−1 dry basis, they ranged from 1.0 to 16.4 MJ kg−1 dry basis at the end of the storage period. Moreover, food wastes exhibited the highest negative correlation with NCVs, whereas plastics have significant positive correlation with both NCVs and TCs. Similarly, TOCs and carbon/nitrogen ratios decreased with the increase in food amounts inside the bales. In addition, textile, wood and yard wastes increase the energy content of the bales slightly over the storage period.

Adsorbable Organic Halogens (AOXs) in Solid Residues from Hazardous and Clinical Waste Incineration

Trace concentrations of a variety of chemicals remain in solid residues following combustion even in properly designed and operated incinerators. In the present study, the adsorbable organic halogen (AOX) levels of the solid residues, i.e., bottom ash, fly ash, and filter cake, were investigated during a 82-day of continuous operation of a Hazardous and Clinical Waste Incinerator. The distribution of halogens in the waste input prior to the incineration was also determined. The AOX levels measured in bottom ash, fly ash and filter cake were in the range of 0.014–1.879, 0.012–0.263, and 0.004–0.062 mg-Cl−/kg, respectively. The AOX levels are significantly low in the fly ash and filter cake due to the post-combustion process in the incinerator. At the end of the 82 days, the total AOX output in the bottom ash, fly ash, and filter cake were 571, 3.71, and 6.26 g, respectively. The partitioning of the total AOX in solid residues was 98.28, 0.64, and 1.08% for the bottom ash, fly ash and filter cake, respectively. This shows that the bottom ash is more contaminated with AOX than the other two residues.

Dietary Exposure to PCDD/Fs Through Animal Products in a Highly Polluted Area in Turkey

ABSTRACT We present an estimation of dietary exposure to PCDD/Fs by animal products in Kocaeli, a highly polluted area in Turkey, based on current food data consumption. The calculation of the PCDD/F intakes by an exposure methodology concerning consumption habits of different receptor groups in Kocaeli was included. The data relate to the PCDD/F levels in food groups of animal origin (milk, egg, meat, chicken, and fish), food consumption rates, and the fractions of locally grown foods in total consumption were statistically assessed. Monte Carlo simulation was used to estimate the ranges of PCDD/F doses through the consumption of animal products. The PCDD/F intakes through the consumption of animal products were calculated to average between 0.4–1.8 pg WHO-TEQ.kg−1 bodyweight (bw).day−1. The results are within the range of 1–4 pg WHO-TEQ.kg−1 bw.day−1, proposed as the tolerable daily intake by the World Health Organization. On the other hand, contributions of the consumption of different foods to the total PCDD/F intake and the results of sensitivity analysis showed that the PCDD/F intake in semi-urban and rural settings was determined primarily by the consumption of milk products, while consumption of meat and fish had a greater importance in urban settings.

Probabilistic Health Risk Assessment of PCDD/Fs in Vegetable Foods at Highly Polluted Area in Turkey

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are highly toxic and persistent organic pollutants that are ubiquitous in the environment. The main pathway of these compounds for human exposure is animal food consumption. On the other hand, plant-derived foods should be also considered for especially vegetarians in an exposure assessment. In this study, dietary intake and health risks of PCDD/Fs have been assessed for adult population living in Kocaeli, Turkey. Exposure levels have been calculated based on a combination of concentration data of locally and non-locally grown vegetable foods and a matrix of environmental exposure factors. The Monte Carlo technique has been applied to calculate dietary exposure and carcinogenic risk distributions. The results have showed that the mean PCDD/F intake via the consumption of vegetable foods are 0.652, 0.672, and 0.661 pg WHO-TEQ kg−1 body weight (bw) day−1 for urban, semi-urban, and rural receptors, respectively. These results are within the range of 1–4 pg WHO-TEQ kg−1 bw day−1 adopted by WHO as the tolerable daily intake. On the other hand, estimated carcinogenic risks related to the PCDD/Fs doses are above the acceptable carcinogenic risk level of 1 in 1,000,000, as proposed by the US EPA. Sensitivity analyses indicate that the cereal consumption has significance effect on the PCDD/F intake for all receptor groups.

AIR DISPERSION MODELING OF VOCs EMITTED FROM MSW LANDFILLS

In Turkey, landfilling is the most preferred method of municipal solid waste management strategy since it is still considered to be the most cost-effective method of waste disposal. Landfills are very complex systems in which various interactive processes proceed simultaneously. Following waste deposition, a landfill gas mainly comprised of methane and carbon dioxide is generated due to the microbial decomposition. Various trace volatile organic compounds (VOCs) besides main components of landfill gas are also produced. The main components and the trace gases from landfills contribute to the greenhouse effect and influence the ozone layer. In addition, adverse effects of landfill gas on human health and vegetation as well as complaints due to unpleasant odor at landfills have been also reported in the literature. Particularly, during landfill operations and after landfill closure, VOCs emitted from landfills should be determined and evaluated due to their probable carcinogenicity. In this study, the dispersion of VOCs emitted at the IZAYDAS landfill (Kocaeli, Turkey) was modeled. The landfill has been in use since 1998, and covers an area of 363,000 m with a total capacity of 3,163,000 m. First, USEPA`s Landfill Gas Emissions Model (LandGEM V3.2) was used to determine the concentrations of the VOCs emitted from the landfill. Then, USEPA’s ISCST3 model (ISC-AERMOD V5.3) was employed for the air dispersion modeling. Following the model inputs such as meteorological parameters, VOC concentrations, digital maps, etc., the wind rose for a five year (2000 – 2004) period and the concentration gradients were obtained.