Lifetime Average Daily Dose Research Articles

Assessment of Uranium in Correlation with Physico-chemical Properties of Drinking Water of Northern Rajasthan

ABSTRACT In the present study, analysis of 238U concentration in 40 drinking water samples collected from different locations of Jodhpur, Nagaur, Bikaner and Jhunjhunu districts of Rajasthan, India has been carried out by using high resolution inductively coupled plasma mass spectroscopy (HR-ICP-MS) technique. The water samples were taken from hand pumps and tube wells having depths ranging from 50 to 800 feet. The measured uranium concentration lies in the range from 0.89 to 166.89 μg l−1 with the mean value of 31.72 μg l−1. The measured uranium content in twelve water samples was found to be higher than the safe limit of 30 μg l−1 as recommended by World Health Organization (WHO, 2011) and US Environmental Protection Agency (USEPA, 2011). Radiological risk calculated in the form of annual effective dose estimated from annual uranium intake ranges from 0.66 to 138.63 μSv y−1 with the mean value of 26.28 μSv y−1. The annual effective dose in two drinking water samples was found to be greater than WHO (2004) recommended level of 100 μSv y−1. Chemical risk calculated in the form of lifetime average daily dose (LAAD) estimated from the water samples varies from 0.02 to 4.57 μg kg−1 d−1 with the mean value of 0.87 μg kg−1 d−1. The lifetime average daily dose (LAAD) of ten drinking water samples was found to be greater than WHO (2011) recommended level of 1 μg kg−1 d−1. The corresponding values of hazard quotient of 48% water samples were found to be greater than unity. A good positive correlation of uranium concentration with total dissolved solids (TDS) and conductance has been observed. However no correlation of uranium concentration with pH was observed. The results revels that uranium concentration in drinking water samples of the study area can cause radiological and chemical threat to the inhabitants.

Radiation dose-dependent risk on individuals due to ingestion of uranium and radon concentration in drinking water samples of four districts of Haryana, India

ABSTRACTUranium gets into drinking water when the minerals containing uranium are dissolved in groundwater. Uranium and radon concentrations have been measured in drinking water samples from different water sources such as hand pumps, tube wells and bore wells at different depths from various locations of four districts (Jind, Rohtak, Panipat and Sonipat) of Haryana, India, using the LED flourimetry technique and RAD7, electronic silicon solid state detector. The uranium (238U) and radon (222Rn) concentrations in water samples have been found to vary from 1.07 to 40.25 µg L−1 with an average of 17.91 µg L−1 and 16.06 ± 0.97 to 57.35 ± 1.28 Bq L−1 with an average of 32.98 ± 2.45 Bq L−1, respectively. The observed value of radon concentration in 43 samples exceeded the recommended limits of 11 Bq L−1 (USEPA) and all the values are within the European Commission recommended limit of 100 Bq L−1. The average value of uranium concentration is observed to be within the safe limit recommended by World Health Organization (WHO) and Atomic Energy Regulatory Board. The annual effective dose has also been measured in all the water samples and is found to be below the prescribed dose limit of 100 µSv y−1 recommended by WHO. Risk assessment of uranium in water is also calculated using life time cancer risk, life time average daily dose and hazard quotient. The high uranium concentration observed in certain areas is due to interaction of ground water with the soil formation of this region and the local subsurface geology of the region.

Rare earth elements in street dust and associated health risk in a municipal industrial base of central China.

The content levels, distribution characteristics, and health risks associated with 15 rare earth elements (REEs) in urban street dust from an industrial city, Zhuzhou, in central China were investigated. The total REE content (∑REE) ranged from 66.1 to 237.4mgkg-1, with an average of 115.9mgkg-1, which is lower than that of Chinese background soil and Yangtze river sediment. Average content of the individual REE in street dust decreased in the order Ce>La>Nd>Y>Pr>Sm>Gd>Dy>Er>Yb>Eu>Ho>Tb>Tm>Lu. The chondrite-normalized REE pattern indicated light REE (LREE) enrichment, a relatively steep LREE trend, heavy REE (HREE) depletion, a flat HREE trend, a Eu-negative anomaly and a Ce-positive anomaly. Foremost heavy local soil and to less degree anthropogenic pollution are the main sources of REE present in street dust. Health risk associated with the exposure of REE in street dust was assessed based on the carcinogenic and non-carcinogenic effect and lifetime average daily dose. The obtained cancer and non-cancer risk values prompt for no augmented health hazard. However, children had greater health risks than that of adults.

Polycyclic aromatic hydrocarbons in imported Sardinops sagax: Levels and health risk assessments through dietary exposure in Nigeria

Polycyclic aromatic hydrocarbons (PAHs) occurrence and assessment of dietary exposure from imported canned sardines (Sardinops sagax) commercially marketed in local stores and supermarkets in Nigeria were evaluated for the first time. PAHs determinations were performed using high performance liquid chromatography (HPLC) (Agilent 1290 model) equipped with UV-VIS diodes array detector (DAD) at λ=210nm and 214nm. The percentage recoveries were higher than 96%. The degree of contamination expressed as total concentration of PAH congeners ranged between 2.53 and 35.55μgkg−1 dry weight (d.w.) at λ=210nm, and 1.30 and 27.93μgkg−1 (d.w.) at λ=214nm. The carcinogenic (TEQBaP) and mutagenic toxicities (MEQBaP) of eight priority PAHs were evaluated. Benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene and indeno[1,2,3-c,d] pyrene contributed significantly to the total carcinogenic equivalents of PAHs. The mutagenic equivalents were largely dominated by chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene and indeno[1,2,3-c,d]pyrene equivalence factors. The estimated lifetime average daily dose (LADD), average annual excess risk (AR), excess cancer rate (ECR), and hazard quotient risk (HQ) were evaluated for adults, children and preteens exposure related risks. The LADD, ECR, AR and HQ of PAHs for carcinogenic and non-carcinogenic risks are relatively higher in preteens than children and adults.

PCDD/Fs profile in ambient air of different types factories and human health risk assessment in Suzhou of Jiangsu province, China

The objective of this study was to assess the potential health risks of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in ambient air of different factories. In this study, fifty-five locations were selected and represented eleven type factories, including municipal solid waste incineration factory (MSWI), hazardous solid waste incineration factory (HSWI), sewage sludge treatment factory (SST), medical waste incineration factory (MWI), electronic factory (EF), pharmaceutical factory in large infusion (PILI), oral medication class factory (OMC), inorganic chemical factory (IC), organic chemical factory (OC), paper mills factory (PM) and mechanical factory (MF). We found that toxic equivalent concentration of PCDD/Fs (TEQ) ranged from 0.236 ± 0.198 to 0.48 ± 0.442 pg I-TEQ/Nm3 in 11 kinds of factories, and average value of TEQs in 11 factories were lower than atmospheric PCDD/F standard (0.6 pg I-TEQ/m3) announced in Japan, and the mean values of TEQ in ambient air of factories were in the decreasing order of MWI > MSWI > PILI > MF > OC > SST > HSWI > OMC > PM > EF > IC. In addition, lifetime average daily doses (LADDs) and their resultant excess cancer risks (ECRs) for workers in those factories were calculated. The results suggested that potential health risk might be occurred in those ambient air.

A quantitative risk assessment for metals in surface water following the application of biosolids to grassland

During episodic rainfall events, land application of treated municipal sludge (‘biosolids’) may give rise to surface runoff of metals, which may be potentially harmful to human health if not fully treated in a water treatment plant (WTP). This study used surface runoff water quality data generated from a field-scale study in which three types of biosolids (anaerobically digested (AD), lime stabilised (LS), and thermally dried (TD)) were spread on micro-plots of land and subjected to three rainfall events at time intervals of 24, 48 and 360h following application. Making the assumption that this water directly entered abstraction waters for a WTP without any grassed buffer zone being present, accounting for stream dilution, and modelling various performance scenarios within the WTP, the aim of this research was to conduct a human health risk assessment of metals (Cu, Ni, Pb, Zn, Cd and Cr), which may still be present in drinking water after the WTP. Different dose-response relationships were characterised for the different metals with reference to the lifetime average daily dose (LADD) and the Hazard Quotient (HQ). The results for the LADD show that child exposure concentrations were highest for Cu when the measured surface runoff concentrations from the LS biosolids treatment were used as input into the model. The results for the HQ showed that of all the scenarios considered, Cu had the highest HQ for children. However, values were below the threshold value of risk (HQ<0.01 - no existing risk). Under the conditions monitored, metal concentrations in the biosolids applied to grassland were not considered to result in a risk to human health in surface water systems.

Electronic cigarettes: a systematic review of available studies on health risk assessment.

This paper primarily aimed to review articles which specifically quantified the risk of electronic cigarette's (e-cigarette) usage via the health risk assessment (HRA) approach. Systematic literature searches were conducted using PubMed search engine databases. Search terms such as "electronic cigarette", "e-cigarette", "electronic nicotine delivery systems", "electronic cigarette liquid", "electronic cigarette vapors", and "health risk assessment" were used to identify the relevant articles to be included in this review. To enable comparison, hazard quotient (HQ) and lifetime cancer risk (LCR) for the chemicals measured in the selected articles were calculated for three of the articles using the formula: [1] HQ=average daily dose (ADD)/reference dose (RfD) or exposure air concentration (EC)/reference concentration (RfC); [2] LCR=lifetime average daily dose (LADD) × cancer slope factor (CSF) or exposure air concentration (EC) × inhalation unit risk (IUR). Four articles pertaining to HRA of e-cigarettes were critically reviewed, three of the papers focused on specific chemicals namely nicotine, propylene glycol (PG), glycerol and 1,2-propanediol, while one article evaluated the health risks posed by heavy metals contained in e-cigarettes. The calculated HQs for the chemicals in this review had large variations. HQs of the six chemicals, i.e. nicotine, PG, glycerol, cadmium, ethylene glycol, nickel, aluminum and titanium, were found to have the potential to contribute to non-carcinogenic health risks. None of the LCR calculated had risks exceeding the acceptable limit. There are limited HRA studies and the ones that were available provided inconsistent scientific evidences on the health risk characterization arising from the usage of e-cigarettes. As such, there is a need to perform more studies on HRA of e-cigarettes by using uniformed and comprehensive steps and similar reference threshold levels of exposures.

Investigation of levels in ambient air near sources of Polychlorinated Biphenyls (PCBs) in Kanpur, India, and risk assessment due to inhalation.

Polychlorinated biphenyls (PCBs) are a class of organic compounds listed as persistent organic pollutant and have been banned for use under Stockholm Convention (1972). They were used primarily in transformers and capacitors, paint, flame retardants, plasticizers, and lubricants. PCBs can be emitted through the primary and secondary sources into the atmosphere, undergo long-range atmospheric transport, and hence have been detected worldwide. Reported levels in ambient air are generally higher in urban areas. Active sampling of ambient air was conducted in Kanpur, a densely populated and industrialized city in the Indo-Gangetic Plain, for detection of 32 priority PCBs, with the aim to determine the concentration in gas/particle phase and assess exposure risk. More than 50 % of PCBs were detected in air. Occurrence in particles was dominated by heavier congeners, and levels in gas phase were below detection. Levels determined in this study are lower than the levels in Coastal areas of India but are at par with other Asian countries where majority of sites chosen for sampling were urban industrial areas. Human health risk estimates through air inhalation pathway were made in terms of lifetime average daily dose (LADD) and incremental lifetime cancer risks (ILCR). The study found lower concentrations of PCBs than guideline values and low health risk estimates through inhalation within acceptable levels, indicating a minimum risk to the adults due to exposure to PCBs present in ambient air in Kanpur.

Assessment of health risk from organochlorine xenobiotics in goat milk for consumers in Poland

The occurrence of organochlorine xenobiotics in goat milk is a one of bioindicators of environmental pollution, and, consequently, food contamination.This study estimates contamination level of goat milk produced at two organic farms in years 2009–2013. Analysis covered determination of 18 organochlorine pesticides, including HCH isomers (α, β, γ, δ), DDT and its metabolites, endosulfan and its derivatives, and methoxychlor. Pesticide content was determined using GCMS method. The detected levels of organochlorine residues in goat milk were low, in most cases below 8 ng g−1 lipids. Among HCH isomers, γ- and β-HCH occurred in the highest concentrations, up to 4.85 ng g−1 lipids. While among DDT metabolites p,p′-DDD dominated, up to 7.86 ng g−1 lipids.The detected residues were below the current maximum residue limits (MRLs) for the pesticides. Considering the average milk consumption in Poland, the goat milk from both farms was safe for consumers’ health. The lifetime average daily dose (LADD) for the sum of the compounds under study ranged within 1.73 × 10−5–1.06 × 10−4 mg kg bw−1 d−1 and were well below the acceptable daily intake (ADI) for particular compounds. This was also confirmed by the values of hazard quotient (HQ), which were very low and ranged within 3.42 × 10−3–5.55 × 10−2.

Trihalometanos y arsénico en el agua de consumo en los municipios de Chinú y Corozal de Colombia: evaluación del riesgo a la salud

In several municipalities in the departments of Cordoba and Sucre in Colombia, the catchment for water supply systems is performed with groundwater from the Morroa aquifer. Disinfection with chlorine gas is the only water purification process and will remain for many decades according to the company providing public services. This research aimed to assess the concentrations of trihalomethanes (THMs) and Arsenic (As) in drinking water and the determination of associated risk from the intake in the population of Chinu and Corozal. The measured variables in samples of drinking water and pools water stored during dry and rainy seasons were THMs, As, Total Organic Carbon (TOC ), residual chlorine, fecal coliform and turbidity, among others. A correlations between fecal coliforms and THMs in its component Chloroform CHCl3 and between turbidity and TOC concentration were found for the two periods in both municipalities. The average value for turbidity concentrations in winter was higher than 0.1 mg/L those in summer for both municipalities. The magnitude of risk was calculated using the methodology of the EPA, trough the Lifetime Average Daily Dose(DDPV).

Level, potential sources of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10) in Naples

Abstract In Naples, particulate matter PM10 associated with polycyclic aromatic hydrocarbons (PAHs) in ambient air were determined in urban background (NA01) and urban traffic (NA02) sites. The principal objective of the study was to determine the concentration and distribution of PAHs in PM10 for identification of their possible sources (through diagnostic ratio - DR and principal component analysis - PCA) and an estimation of the human health risk (from exposure to airborne TEQ). Airborne PM10 samples were collected on quartz filters using a Low Volume Sampler (LVS) for 24 h with seasonal samples (autumn, winter, spring and summer) of about 15 days each between October 2012 and July 2013. The PM10 mass was gravimetrically determined. The PM10 levels, in all seasons, were significantly higher (P The concentration of Benzo[a]Pyrene, BaP (EU and National limit value: 1 ng m−3 in PM10), varied from 0.065 ng m−3 during autumn time to 0.872 ng m−3 in spring time (NA01) and from 0.120 ng m−3 during autumn time to 1.48 ng m−3 of winter time (NA02) with four overshoots. In NA02 the trend of Σ12 PAHs was comparable to NA01 but were observed higher values than NA01. In fact, the mean concentration of Σ12 PAHs, in urban-traffic site was generally 2 times greater than in urban-background site in all the campaigns. PAHs with 5 and 6 ring, many of which are suspected carcinogens or genotoxic agents, (i.e Benzo[a]Pyrene, Indeno[1,2,3-cd]Pyrene, Benzo[b]Fluoranthene, Benzo[k]Fluoranthene and Benzo[g,h,i]Perylene), had a large contribution (∼50–55%) of total PAHs concentration in PM10 in two sites and in each of the campaigns. Diagnostic ratio analysis and PCA suggested a substantial contributions from traffic emission with minimal influence from coal combustion and natural gas emissions. In particular diesel vehicular emissions were the major source of PAHs at the studied sites. The use of Toxicity Equivalence Quantity (TEQ) concentration provide a better estimation of carcinogenicity activities; health risk to adults and children associated with PAHs inhalation was assessed by taking into account the lifetime average daily dose and corresponding incremental lifetime cancer risk (ILCR). The ILCR was within the acceptable range (10−6–10−4), indicating a low health risk to residents in these areas.

The estimation of consumer health risk associated with organochlorine xenobiotics in hard smoked cheese in Poland

The aim of this study was to estimate the health risks associated with consumption of smoked cheeses, which are popular in Poland. The analysis covered polychlorinated biphenyl (PCB) indicator congeners (ndl-PCBs: PCB 28, PCB 52, PCB 101, PCB 138, PCB 153, PCB 180), dioxin-like PCBs (dl-PCBs): non-ortho (PCB 77, PCB 81, PCB 126, PCB 169) and mono-ortho (PCB 105, PCB 114, PCB 118, PCB 156, PCB 157), as well as organochlorine pesticides (OCPs: αHCH, βHCH, γHCH, heptachlor, aldrin, heptachlor epoxid isomer B, dieldrin, pp'DDE op′DDD, pp′DDT, pp′DDD, op′DDT, endrin). The pesticide residues detected in the examined cheese were below the maximum residues levels. The estimated daily intake [lifetime average daily dose (LADD)] referring to the sum of the compounds varied within 4.21·10−7–3.92·10−6 mg·kg−1·day−1 and was significantly lower than the tolerable daily intake/acceptable daily intake (TDI/ADI) for individual compounds. The health hazard quotient, being the exact measure of the magnitude of exposure potential or a quantifiable potential for developing non-carcinogenic health effects after an averaged exposure period, was also very low, ranging from 2.87·10−6 to 5.32·10−5. The obtained results confirmed that the intake of rennet cheese does not pose any consumer health risk in Poland.

Radiological and chemical toxicity due to ingestion of uranium through drinking water in the environment of Bangalore, India

Groundwater samples collected from 96 bore wells in the study area (city of Bangalore) were analysed for concentration of natural uranium using laser-induced fluorimetry. The risk to the population of the region associated with radiological and chemical toxicity of uranium due to its ingestion through drinking water over a lifetime was estimated. The concentration of uranium was found to be in the range 0.136 to 2027.5 μg L−1 with an average value of 92.42 μg L−1. In the present study, about 61% of the samples show concentrations of uranium within the safe limit of 30 μg L−1 as set by the world health organisation. The radiological risk estimated as lifetime cancer risk is in the range 4.3 × 10−7 to 6.4 × 10−3 with an average of 2.9 × 10−4. The chemical toxicity risk measured as lifetime average daily dose is found to range from 0.005 to 75.42 μg kg−1 d−1. The reference dose estimated as 1.12 μg kg−1 d−1 was used to assess the chemical toxicity. The results indicate that the chemical toxicity due to ingestion of uranium through drinking water is of more concern than the radiological toxicity. The present study, being the first of its kind in this region, will augment the database of uranium in groundwater.

A new method for setting guidelines to protect human health from agricultural exposure by using chlorpyrifos as an example.

Guidelines set by various agencies for the control and management of chlorpyrifos cover a wide range of values reflecting difficulties in the procedures for their development. To overcome these difficulties a new method to set guidelines would be developed. Published data derived from epidemiological investigations on human populations would be used to develop a dose-response relationship for chlorpyrifos allowing the calculation of threshold values which can be used as guidelines. Data from the scientific literature on human populations were collected to evaluate the adverse response doses for a range of health effects. The Cumulative Frequency Distribution (CFD) for the minimum levels of adverse effects measured in terms of the Lifetime Average Daily Dose (LADD(D)) and the Absorbed Daily Dose for neurological (ADD(DN)) and non-neurological effects were used. Linear regression equations were fitted to the CFD plots giving R 2 values of 0.93 and 0.86 indicating a normal distribution of the data. Using these CFD plots, the chronic and acute threshold values were calculated at the 5% cumulative frequency level for chlorpyrifos exposure giving values at 0.5 µg/kg/d and 3 µg/kg/d respectively. Guidelines set using this technique at the values at 0.5 µg/kg/d and 3 µg/kg/d for chronic and acute exposure respectively provide an alternative to the currently used biological endpoint and safety factor method.

Development of toxicity values and exposure estimates for tetrabromobisphenol A: application in a margin of exposure assessment.

Tetrabromobisphenol A (TBBPA) is used in a diverse array of products to improve fire safety. The National Toxicology Program (NTP) recently completed a 2‐year bioassay for TBBPA. The objective of the present study was to develop a cancer‐based and a non‐cancer based toxicity value and to compare such to appropriate estimates of human exposure. Data from the NTP 2‐year and 13‐week studies were selected to develop candidate toxicity values. Benchmark dose modeling and subsequent evaluation of candidate values resulted in selection of an oral reference dose (RfD) of 0.6 mg kg−1 day−1 based on uterine hyperplasia in rats and an oral cancer slope factor (OSF) of 0.00315 per mg kg−1 day−1 based on an increased incidence of uterine tumors in rats. Lifetime average daily dose (LADD) estimates ranged from 2.2 E−7 to 3.9 E−6 mg kg−1 day−1 based on age‐adjusted exposures to TBBPA via breast milk consumption, dietary intake, soil/dust ingestion and drinking water ingestion in infants, young children, older children and adults. Average daily dose (ADD) estimates ranged from 3.2 E −7 to 8.4 E−5 mg kg−1 day−1. Resulting margin of exposure (MOE) values were > 800 000 for non‐cancer endpoints and > 32 000 000 for cancer‐based endpoints. These data collectively indicate a low level of health concern associated with exposures to TBBPA based on current data. It is anticipated that the exposure estimates, along with the toxicity values described within, should be informative for understanding human health hazards associated with TBBPA. Copyright © 2015. The Authors. Journal of Applied Toxicology Published by John Wiley & Sons Ltd.

Caramel color in soft drinks and exposure to 4-methylimidazole: a quantitative risk assessment.

Caramel color is added to many widely-consumed beverages as a colorant. Consumers of these beverages can be exposed to 4-methylimidazole (4-MEI), a potential carcinogen formed during its manufacture. California’s Proposition 65 law requires that beverages containing 4-MEI concentrations corresponding to exposures that pose excess cancer risks > 1 case per 100,000 exposed persons (29 μg 4-MEI/day) carry warning labels. Using ultrahigh-performance liquid chromatography-tandem mass spectrometry, we assessed 4-MEI concentrations in 12 beverages purchased in California and a geographically distant metropolitan area (New York) in which warning labels are not required. In addition, we characterized beverage consumption by age and race/ethnicity (using weighted means calculated from logistic regressions) and assessed 4-MEI exposure and resulting cancer risks and US population cancer burdens attributable to beverage consumption. Data on beverage consumption were obtained from the National Health and Nutrition Examination Survey, dose-response data for 4-MEI were obtained from the California Environmental Protection Agency Office of Environmental Health Hazards Assessment, and data on population characteristics were obtained from the U.S. Census Bureau. Of the 12 beverages, Malta Goya had the highest 4-MEI concentration (915.8 to 963.3μg/L), lifetime average daily dose (LADD - 8.04x10-3 mg/kgBW-day), lifetime excess cancer risk (1.93x10-4) and burden (5,011 cancer cases in the U.S. population over 70 years); Coca-Cola had the lowest value of each (4-MEI: 9.5 to 11.7μg/L; LADD: 1.01x10-4 mg/kgBW-day; risk: 1.92x10-6; and burden: 76 cases). 4-MEI concentrations varied considerably by soda and state/area of purchase, but were generally consistent across lots of the same beverage purchased in the same state/area. Routine consumption of certain beverages can result in 4-MEI exposures > 29 μg/day. State regulatory standards appear to have been effective in reducing exposure to carcinogens in some beverages. Federal regulation of 4-MEI in caramel color may be appropriate.

Levels, potential sources and human health risk of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM(10)) in Kumasi, Ghana.

Airborne particulate samples were collected on quartz filters to determine the concentrations, sources and health risks of polycyclic aromatic hydrocarbons (PAHs) in air in Kumasi, Ghana. A total of 32 air samples were collected in Kwame Nkrumah University of Science and Technology (KNUST) campus (pristine site) and city centre (CC). Samples were extracted with 1:2 v/v acetone/hexane mixture prior to GC-MS analyses. The sum of concentrations of 17 PAHs in air ranged from 0.51 to 16 (KNUST) and 19-38 ng/m(3) (CC). The concentration of benzo[a]pyrene, BaP, ranged from below detection limit to 0.08 ng/m(3) (KNUST) and 1.6 to 5.6 ng/m(3) (CC). Chemical mass balance model showed that PAHs in air in Kumasi were mainly from fuel combustion. The total BaP equivalent concentration (BaPeq) in CC was 18 times higher compared to KNUST; based on the European Legislation and Swedish and UK Standards for BaP in air, CC could be classified as highly polluted. Estimated carcinogenicity of PAHs in terms of BaPeq indicated that BaP was the principal PAH contributor in CC (70%). Health risk to adults and children associated with PAH inhalation was assessed by taking into account the lifetime average daily dose and corresponding incremental lifetime cancer risk (ILCR). The ILCR was within the acceptable range (10(-6) to 10(-4)), indicating low health risk to residents.

Chemical characteristics and mutagenic activity of PM2.5 at a site in the Indo-Gangetic plain, India

Airborne fine particulate matter PM2.5 was collected from May 2010 to December 2012 at Agra, a semi-urban site in north-central India. PM2.5 samples were chemically characterized for 16 polycyclic aromatic hydrocarbons by gas chromatography. PM2.5 values varied between 8.4 and 300µgm−3 with 55% of the values exceeding the 24h average NAAQ (National Ambient Air Quality) standard of 65µgm−3. Particle associated total PAHs ranged between 8.9 and 2065ngm−3 with a mean value of 880.8ngm−3 during the sampling period, indicated an alarming level of pollution in Agra. Strong relationship was observed between PM2.5 and total PAHs (r=0.88), suggesting an increasing PAHs concentration with increasing PM2.5 mass. On a mass basis 3-ring and 4-ring compounds were dominant. Seasonal variation in mass concentration of PAHs was observed with high concentration in winter followed by post monsoon, summer and monsoon. This seasonal pattern could be attributed to differences in source strength and climatic conditions. PAHs concentration were also observed to be negatively correlated with the meteorological parameters i.e. temperature, solar radiation, relative humidity and wind speed. Molecular diagnostic ratios revealed vehicular emissions and combustion of wood and coal as the probable sources. The estimated carcinogenicity of PAHs in terms of benzo(a)pyrene toxic equivalency (B[a]PTEQ) was assessed and confirmed that benzo[a]pyrene was the dominant PAH contributor (3.64%). Health risk of adults and children by way of PAHs was assessed by estimating the lifetime average daily dose (LADD) and corresponding incremental lifetime cancer risk (ILCR) using USEPA guidelines. The assessed cancer risk (ILCR) was found to be within the acceptable range (10−6–10−4). The particulate samples indicated the presence of both base pair and frame shift mutagens using TA98 and TA100 strains of Salmonella typhimurium. Enhanced mutagenic response was observed in the presence of enzyme activation.

Health risk characterization for exposure to benzene in service stations and petroleum refineries environments using human adverse response data

Health risk characterization of exposure to benzene in service stations and petroleum refineries has been carried out in previous studies using guideline values set by various agencies. In this work, health risk was characterized with the exposure data as cumulative probability distribution (CPD) plots but using human epidemiological data. This was achieved by using lowest observable adverse effects levels (LOAEL) data plotted as cumulative probability lowest effects distribution (CPLED). The health risk due to benzene was characterized by using probabilistic methods of hazard quotient (HQ50/50 and HQ95/5), Monte-Carlo simulation (MCS) and overall risk probability (ORP). CPD relationships of adverse health effects relationships and exposure data were in terms of average daily dose (ADD) and lifetime average daily dose (LADD) for benzene. For service station environments HQ50/50 and HQ95/5 were in a range of 0.000071–0.055 and 0.0049–21, respectively. On the other hand, the risk estimated for petroleum refinery environments suggests higher risk with HQ50/50 and HQ95/5 values ranging from 0.0012 to 77 and 0.17 to 560, respectively. The results of Monte-Carlo risk probability (MRP) and ORP indicated that workers in petroleum refineries (MRP of 2.9–56% and ORP of 4.6–52% of the affected population) were at a higher risk of adverse health effects from exposure to benzene as compared to exposure to benzene in service station environments (MRP of 0.051 –3.4% and ORP of 0.35–2.7% affected population). The adverse effect risk probabilities estimated by using the Monte-Carlo simulation technique and the ORP method were found to be generally consistent.

Residential Exposures to Arsenic and Hexavalent Chromium from CCA Wood

Residential Exposures to Arsenic and Hexavalent Chromium from CCA WoodAbstract Number:1551 Ky Gress* and Lena Ma Ky Gress* University of Florida, United States, E-mail Address: [email protected] Search for more papers by this author and Lena Ma University of Florida, United States, E-mail Address: [email protected] Search for more papers by this author AbstractArsenic exposure from wood treated with chromated copper arsenate (CCA) remains a concern due to its presence around homes. These studies explored exposure to arsenic (As) and hexavalent chromium (CrVI) from CCA wood in several settings, including children’s exposure outside apartment buildings, homeowner’s exposure from power-washing CCA decking and animal exposure from living in zoo enclosures made from CCA wood. Children’s exposure to As from 2-story staircases was estimated through determination of bioaccessible soil As and wipe sampling of dislodgeable arsenic (DA) on hand railings, steps and surfaces of objects stored under staircases. Total As concentrations in soil samples ranged from 1.2–66.6 mg/kg. Lifetime average daily doses from ingestion of DA and soil ranged from 8.1 × 10-6 to 3.0 × 10-5 mg/kg/day. In Florida, homeowners typically powerwash CCA wood using bleach solutions, which can oxidize CrIII to CrVI, a known carcinogen. This study evaluated potential exposures to As and Cr(VI) on the wood surface, in rinsate and in nearby soil, finding concentrations of As in rinsate up to 1.6 mg/L. CCA wood is commonly found on farms and in zoos. Captive animals living in enclosures made from CCA wood can be in constant contact with arsenic-contaminated soil. Soil sampling inside animal enclosures at a zoo in Florida found widespread arsenic contamination, with concentrations up to 9 times higher than allowed at industrial sites. This study is ongoing and includes biomonitoring of animals, including endangered species in a captive breeding program.