Chronic Daily Intakes Research Articles

Personal Protective Equipment as a Potential Source of Phthalate Exposure during the COVID-19 Pandemic

Personal protective equipment (PPE)—especially face masks, face shields, and gloves—was used to minimize the spread of COVID-19. PPE is primarily made of plastic materials with various plastic additives, such as phthalate plasticizers. Phthalates are linked with various adverse health effects. Therefore, this study investigated the amounts of six commonly used phthalates (DBP, BBP, DEHP, DnOP, DINP, and DIDP) in different types of PPE samples collected during the pandemic. Gas chromatography–mass spectrometry (GC–MS) was used to detect six selected phthalates and other organic chemicals in PPE samples. The quality of data was ensured using certified reference materials, internal standards, procedural blanks, and replicate analyses. The total phthalate content found in face shields and face masks was in the range of 0.29 µg/g to 942.60 µg/g, with DBP, DEHP, and DINP detected most frequently. A health risk assessment concluded that the determined levels were not expected to pose adverse health effects on the wearer. However, the findings of this study suggest that chronic daily intakes of phthalates from two vinyl glove samples with phthalate content exceeding 11% and 14% (w/w) of the glove’s weight may potentially increase the risk of cancer in humans. In addition to the target phthalates, flame retardants and other plasticizers (e.g., organophosphates and dioctyl isophthalate) were tentatively identified in various PPE samples.

Occurrence, source, and risk assessment of neonicotinoid insecticides in the Huai River, China

Neonicotinoids (NEOs) are the most widely used insecticides in the world. Nevertheless, the occurrence and distribution of NEOs in agricultural areas are not well understood. This study investigated the concentration, sources, ecological risks, and health risks of eight NEOs in the water of the Huai River, which flows through a typical agricultural area in China. The total concentration of NEOs in the river water ranged from 1.02 to 191.2 ng L−1, with an average of 64.1 ng L−1. Thiamethoxam was the dominant compound, with an average relative contribution of 42.5%. The average concentration of the total NEOs in downstream was significantly higher than that in upstream (p < 0.05). This may be related to the intensity of agricultural activities. The riverine NEO fluxes increased by approximately 12 times from the upper site to the lower site. More than 1.3 tons of NEOs in 2022 were transferred into Lake Hongze, the largest regulative lake on the Eastern Route of the South-to-North Water Diversion Project. Nonpoint sources were the major contributor to the total NEO inputs, and water use was the main output pathway. The risk assessment indicated that the individual NEOs in the river water presented low ecological risks. The NEO mixtures would produce chronic risks to aquatic invertebrates in 50% of the sampling sites, which were mostly distributed in downstream. Thus, more attention should be given to the downstream. Based on the Monte Carlo simulation, the health risks of NEOs via water consumption were estimated. The maximum chronic daily intakes were 8.4 × 10−4, 2.25 × 10−4, 1.27 × 10−4, 1.88 × 10−4 mg kg−1 day−1 for boys, girls, men, and women, respectively, which were approximately 2 orders of magnitude lower than the acceptable daily intake. Therefore, river water consumption would not be a concern for the public health.

Comparing risk of disinfection byproducts in drinking water under variable scenarios of seawater intrusion

The higher levels of halides in seawater increase bromide and iodide in the coastal aquifers, leading to higher concentrations of halogenated disinfection byproducts (DBPs). The populations in the coastal areas are susceptible to increased concentrations of DBPs while many DBPs are cyto- and genotoxic to mammalian cells, and are possible/probable human carcinogens. The implications of seawater intrusion on the concentrations of trihalomethanes (THMs) and haloacetic acids (HAAs), and the risks were analyzed by adding 0.0–2.0 % seawater (SW) (by volume) and chlorine to groundwater. Bromide and iodide concentrations in groundwater (0.0 %SW) were observed as 42.5 and non-detected (ND) μg/L respectively. With 2.0 %SW, these were spiked up to 1100 and 2.1 μg/L respectively. The most common THMs (THM4), iodinated THMs (I-THMs) and HAAs were 30.4, 0.13 and 27.9 μg/L for 0.0 % SW respectively. With 2.0 %SW, these values were 106.3, 1.6 and 72.9 μg/L, respectively. At 0.0 %SW, averages of chronic daily intakes (CDI) for THM4, HAAs and I-THMs were 2.61 × 10−4, 2.26 × 10−4 and 7.69 × 10−7 mg/kg/day respectively, which were increased to 9.97 × 10−4, 4.70 × 10−4 and 9.47 × 10−6 mg/kg/day, respectively for 2.0 %SW. For 0.0 %SW, overall cancer risks from few DBPs was 3.09 × 10−5 (6.46 × 10−6 - 7.23 × 10−5) while at 1.0 % and 2.0 %SW, risks were 4.88 × 10−5 (1.26 × 10−5–1.08 × 10−4) and 4.11 × 10−5 (1.21 × 10−5–9.28 × 10−5) respectively. The reduction of risks for 2.0 %SW was due to the increase of bromoform (TBM), and decrease in bromodichloromethane (BDCM) and dibromochloromethane (DBCM) at 2.0 %SW. The disability-adjusted life years (DALY) loss showed an increasing trend from 0.0 %SW (DALY: 77.30) to 1.0 %SW (DALY: 122.0) while an increase to 2.0 %SW showed a decrease in DALY (DALY: 102.8). Future study on toxicity of other regulated and emerging DBPs is warranted to better predict cancer risks.

Maternal exposure to atmospheric PM2.5 and fetal brain development: Associations with BAI1 methylation and thyroid hormones

Maternal exposure to atmospheric fine particulate matter (PM2.5) during pregnancy is associated with adverse fetal development, including abnormal brain development. However, the underlying mechanisms and influencing factors remain uncertain. This study investigated the roles of DNA methylation in genes involving neurodevelopment and thyroid hormones (THs) in fetal brain development after maternal exposure to PM2.5 from e-waste. Among 939 healthy pregnant women recruited from June 2011 to September 2012, 101 e-waste-exposed and 103 reference mother-infant pairs (204 pairs totally) were included. Annual ground-level PM2.5 concentrations over e-waste-exposed area (116.38°E, 23.29°N) and reference area (116.67°E, 23.34°N) in 2011, 2012 were obtained by estimates and maternal exposure was evaluated by calculating individual chronic daily intakes (CDIs) of PM2.5. Methylation and THs including thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) level were measured in umbilical cord blood collected shortly after delivery. We found higher ground-level PM2.5 concentrations led to greater individual CDI of PM2.5 in e-waste-exposed pregnant women. After adjustment for gender and birth BMI, significant mediation effects on the adverse associations of maternal PM2.5 exposure with birth head circumference were observed for methylations at positions +13 and + 32 (respectively mediated proportion of 9.8% and 5.3%, P < 0.05 and P < 0.01) in the brain-specific angiogenesis inhibitor 1 (BAI1) gene, but not for methylations in the catenin cadherin-associated protein, alpha 2 (CTNNA2) gene. BAI1 (position +13) methylation was also significantly correlated with FT3 levels (rs = −0.156, P = 0.032), although maternal CDI of PM2.5 was positively associated with higher odds of abnormal TSH levels (OR = 5.03, 95% CI: 1.00, 25.20, P = 0.05) rather than FT3 levels. Our findings suggest that methylation (likely linked to THs) in neonates may play mediation roles associated with abnormal brain development risk due to maternal exposure to atmospheric PM2.5 from e-waste.

Groundwater quality and health assessments based on heavy metals and trace elements content in Dakhla Oasis, New Valley Governorate, Egypt

ABSTRACT This study is searching for some crucial physicochemical properties of groundwater samples collected from eleven outlets in Dakhla Oasis, Egypt, including the pH-value, electrical conductivity (EC), total dissolved solids (TDS), in addition to the concentrations of heavy metals and trace elements. In total 21 elements were analyzed using inductively coupled plasma spectrometry (ICP-OES). To categorize the water class: Chronic daily intakes (CDI), water quality index (WQI) and hazard risk (HR) were computed for the 21 elements in the water samples. Some biological parameters such as levels of urea, creatinine, and the tumor marker CEA were measured. The obtained results showed that the pH-values (6.12 to 6.56) for water samples are within the acceptable limits of the WHO. Results showed, also, that EC (274 to 532 μS/cm), TDS (175 to 340 ppm) besides, the level of measured 21 elements were lower than the values allowed by World Health Organization (WHO) and US Environmental Protection Agency (USEPA). Additionally, the reached data were comparable to other internationally published figures. It is emphasized that the data obtained for WQI confirmed that water from all the sampling points was of expedient quality. Based on the obtained data and the evaluated parameters, it can be concluded that the groundwater samples of the studied areas are of excellent quality; they do not pose any health risks to the local citizens, and are safe for their domestic consumption. Moreover, the results of urea, creatinine, and CEA analyses showed very few abnormal cases, which confirmed, again, that the groundwater in the studied areasdid not pose a risk to human health.

Probabilistic approach for health hazard assessment of trihalomethanes through successive showering events.

Trihalomethanes (THMs) are common disinfection by-products in chlorinated tap waters. They can cause various cancers and non-cancer health hazards. Ingestion, dermal contact, and inhalation are the three exposure routes considered in the THM hazard or risk assessments. Among these, inhalation hazard is generally calculated by assuming the initial concentration as zero. This assumption fails to address the case of continuous or successive showers that can happen in shared showering facilities such as student hostels or gymnasiums. In the present study, the leftover THM concentration from the previous bath was considered to assess the chronic daily intakes (CDI) and hazard index (HI) for successive showers. For this, tap water of a university campus was analyzed to understand the extent of THM exposure at consumer points and the result obtained was used for the hazard assessment. Total THM concentrations varied from 0.51 to 68.9µg L-1. To address the variability of the model input parameters, 50,000 iterations of Monte Carlo simulation were carried out. Maximum HI values of 7.94E - 02 ± 3.63E - 02, and 6.69E - 02 ± 3.08E-02 were observed for the 1st shower for females and males, respectively. This value increased exponentially up to the 5th shower and thereafter, the value was constant. The methodology followed in the present study successfully determines the risk and hazard of THMs through successive showers.

Prediction of Trihalomethanes in water supply of Chattogram city by empirical models and cancer risk through multi-pathway exposure

This study predicts the possible occurrence of trihalomethanes (THMs) in water supply of Chattrogram city in Bangladesh, and life time cancer risk from multi-pathway intakes of the trihalomethanes (THMs) to the city dwellers. A total of 11 water samples were collected from the distribution network of the city, and few water quality parameters were analyzed in the study. Three empirical models developed by Amy et al. (1998), Rathbun (1996), and Malcolm Pirnie (1993) were used to estimate the level of THMs from measured water quality data, and were denoted as MODEL1, MODEL2 and MODEL3, respectively in the study. Lifetime cancer risk was estimated using predicted chronic daily intakes (CDI) of THMs' species for different exposure routes (ingestion, inhalation and dermal). The total concentrations of THMs ranged between 20 and 440 μg/L, 95–215 μg/L and 162–249 μg/L were predicted by MODEL1, MODEL2 and MODEL3, respectively. An average lifetime cancer risk was predicted as 1.4 × 10−4, 1.1 × 10−4 and 2.9 × 10−4 for oral, inhalation and dermal exposure, respectively from the water supply of the city. Percent contribution to total lifetime cancer risk were predicted as 50, 40 and10 for oral ingestion, inhalation and dermal absorption, respectively. The study revealed that lifetime cancer risk values were higher than minimum risk level set by United States Environmental Protection Agency. The findings of possible occurrence of THMs in the water supply and associated cancer risk might be beneficial as baseline data for further investigation, and help the decision makers regarding the formulation of standards and legislations of THMs.

PM2.5-bound PAHs exposure linked with low plasma insulin-like growth factor 1 levels and reduced child height

BackgroundExposure to atmospheric fine particle matter (PM2.5) pollution and the absorbed pollutants is known to contribute to numerous adverse health effects in children including to growth. ObjectiveThe aim of this study was to evaluate exposure levels of atmospheric PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in an electronic waste (e-waste) polluted town, Guiyu, and to investigate the associations between PM2.5-PAH exposure, insulin-like growth factor 1 (IGF-1) levels and child growth. MethodsThis study recruited 238 preschool children (3–6 years of age), from November to December 2017, of which 125 were from Guiyu (an e-waste area) and 113 were from Haojiang (a reference area). Levels of daily PM2.5 and PM2.5-bound ∑16 PAHs were assessed to calculate individual chronic daily intakes (CDIs). IGF-1 and IGF-binding protein 3 (IGFBP-3) concentrations in child plasma were also measured. The associations and further mediation effects between exposure to PM2.5 and PM2.5-bound PAHs, child plasma IGF-1 concentration, and child height were explored by multiple linear regression models and mediation effect analysis. ResultsElevated atmospheric PM2.5-bound ∑16 PAHs and PM2.5 levels were observed in Guiyu, and this led to more individual CDIs of the exposed children than the reference (all P < 0.001). The median level of plasma IGF-1 in the exposed group was lower than in the reference group (91.42 ng/mL vs. 103.59 ng/mL, P < 0.01). IGF-1 levels were negatively correlated with CDIs of PM2.5, but not with CDIs of PM2.5-bound ∑16 PAHs after adjustment. An increase of 1 μg/kg of PM2.5 intake per day was associated with a 0.012 cm reduction of child height (95% CI: −0.014, −0.009), and similarly, an elevation of 1 ng/kg of PM2.5-bound ∑16 PAHs intake per day was associated with a 0.022 cm decrease of child height (95% CI: −0.029, −0.015), both after adjustment of several potential confounders (age, gender, family cooking oil, picky eater, eating sweet food, eating fruits or vegetables, parental education level and monthly household income). The decreased plasma IGF-1 concentration mediated 15.8% of the whole effect associated with PM2.5 exposure and 23.9% of the whole effect associated with PM2.5-bound ∑16 PAHs exposure on child height. ConclusionExposure to atmospheric PM2.5-bound ∑16 PAHs and PM2.5 is negatively associated with child height, and is linked to reduced IGF-1 levels in plasma. This may suggest a causative negative role of atmospheric PM2.5-bound exposures in child growth.

Behavioral Flexibility in Alcohol-Drinking Monkeys: The Morning After.

Heavy alcohol drinking has aspects of inflexible behavior. This study addressed the consequences of chronic alcohol drinking on cognitive and sensory-motor domains of behavioral flexibility in rhesus monkeys. Behavioral flexibility was assessed in 12 monkeys (n=9, ethanol [EtOH] drinkers) with a set-shifting visual discrimination procedure before alcohol self-administration and while maintaining consumption of 1.5g/kg/d EtOH. Task performance was assessed in the morning after ~18hours of drinking 1.5g/kg, and 1hour before the next day's drinking session began. The first 10 set-shifting sessions had the original (preethanol) test parameters and were used to determine retention of preethanol performance. Then, an effect of sensory-motor challenge (60% reduction in the size of the discriminative stimuli) on performance was assessed during 10 additional sessions. There were no average group-dependent differences in the performance between control and EtOH groups at the preethanol time-point. The daily consumption of 1.5g/kg/d produced binge alcohol intakes in 7 of 9 monkeys (blood EtOH concentration [BEC≥80mg/dl]). Chronic daily intakes of 1.5g/kg had no effect on retention of the task in the sober state. However, when challenged with a reduction in the size of the stimuli, daily 1.5g/kg EtOH resulted in a decrement in performance due to an increase in the number of errors. Rhesus monkeys consuming 1.5g/kg alcohol daily perform equally as could as control monkeys in retention of a well-learned cognitive task. However, this pattern of daily alcohol intake robustly decreased the ability to flexibly adjust behavior when confronted with novel changes to perceptual stimuli.

Evaluation of PM1, PM2.5, and PM10 exposure and the resultant health risk of preschool children and their caregivers

Preschool children have a higher respiratory rate per unit body weight than adults, and their respiratory systems are not mature. Hence, children may have more health risks associated with particulate matter (PM) exposure. In this study, we assessed the exposure of preschool children and their caregivers to PM and the resulting health risks. The PM concentrations at heights of 60–80 cm (preschool children) and 150 cm (adults) were measured at ten indoor and eight outdoor sites in the Taipei metropolitan area from March 2015 to February 2017. Four PM2.5 and seven PM10 indoor measurements exceeded the indoor air quality standard of Taiwan, whereas only two PM2.5 outdoor measurements exceeded the ambient air quality standard. The outdoor PM concentrations were related to traffic emissions, whereas the indoor PM concentrations were associated with ventilation rate and occupant density. The chronic daily PM1, PM2.5, and PM10 intakes of preschool children were notably higher than those of adults. In addition, the hazard quotient resulting from PM2.5 exposure indicated a significant health risk for preschool children (93.74% greater than 1). Consequently, reducing the exposure of preschool children to PM2.5 is an emerging issue in the Taipei metropolitan area.

Human health risk from exposure to metals through fish and shellfish ingestion in Saudi Arabia

In this study, human exposure and risks of metals through fish ingestion were predicted. Concentrations of 10 metals (Cd, As, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn) in 17 commonly eaten fish species in Saudi Arabia were characterized. Using the fish ingestion patterns, chronic daily intakes of metals among the Saudi and expatriate populations were predicted to be in the ranges of 8.89 × 10−06–1.08 × 10−02 and 6.59 × 10−06–7.97 × 10−03 mg/kg/day, respectively. The average cancer risks from inorganic arsenic were 2.76 × 10−05 and 2.09 × 10−05 for Saudi and expatriate, and the ranges were 1.61 × 10−09–1.58 × 10−03 and 2.64 × 10−09–1.27 × 10−03, respectively. The predicted risks were much lower than the previously reported risks. There were 47.4% and 42.4% chances that cancer risks would be higher than 1.0 × 10−05 (10 per million) among Saudi and expatriate, respectively. The average cumulative hazard index (HI) for Saudi and expatriate were 0.324 and 0.239 with the ranges of 0.0142–7.26 and 0.017–6.43, respectively. Approximately 3.06% and 1.56% cases among Saudi and expatriate had HI greater than unity, indicating possible health concern, respectively. Through comprehensive understanding of exposure and risks, strategies can be adopted to protect human health.

Prediction of human exposure and health risk assessment to trihalomethanes in indoor swimming pools and risk reduction strategy

ABSTRACTExposure to disinfection by-products can occur through various pathways such as inhalation, dermal contact, and ingestion for swimmers. In the present study, swimming exposure to disinfection by-products through ingestion and dermal route at the indoor swimming pool was assessed and health risks caused by exposure to these compounds were studied. Water samples were first collected from Eslamshahr (Tehran, Iran) and water quality parameters were analyzed. Then, a multi-pathway model was conducted to assess and estimate the chronic daily intakes (CDI) and lifetime cancer risk (LTCR). The results showed that the mean values of CDIs for chloroform, DCBM, DBCM, and bromoform were 2.12 × 10−6, 7.35 × 10−7, 8.12 × 10−9, and 1.28 × 10−8 mg/kg-d, respectively through ingestion pathways, and 3.95 × 10−5, 1.56 × 10–6, 1.88 × 10–8, and 3.08 × 10−8 mg/kg-d through the dermal pathway, respectively. Also our findings showed that the mean of total LTCR for swimmers was 4.63 × 10−8 and the cancer risks through dermal route were higher than ingestion route. Also, cancer risks of chlorinated compounds were higher to implement a set of strategies in order to improve water treatment of swimming pools.

Occurrence and Health-Risk Assessment of Trace Metals in Raw and Boiled Drinking Water from Rural Areas of China

In order to assess the exposure of rural residents to trace metals via drinking water ingestion, 222 drinking water samples of rural areas from 8 provinces in China were collected and 18 trace metals analyzed by inductively coupled plasma mass spectrometer (ICP-QMS). Based on metal concentrations, the health-risk assessment such as chronic daily intakes (CDI) and hazard quotient (HQ) were calculated. Results showed that most metals occurred in the drinking water at very low concentrations, indicating a general good quality, while the concentrations of As, Pb and Zn in some samples from Qinghai, Yunnan and Hunan provinces were higher than World Health Organization (WHO) and Chinese guidelines for drinking water. The values of CDI and HQ indicated a negligible health risk for most Chinese rural residents via drinking water. However, high concentrations of As in drinking water from Qinghai province would pose a serious risk to the local inhabitants. More attention and intensive study should be paid to Zn, Pb and As contents.

Disinfection Byproducts in Drinking Water and Evaluation of Potential Health Risks of Long-Term Exposure in Nigeria.

Levels of trihalomethanes (THMs) in drinking water from water treatment plants (WTPs) in Nigeria were studied using a gas chromatograph (GC Agilent 7890A with autosampler Agilent 7683B) equipped with electron capture detector (ECD). The mean concentrations of the trihalomethanes ranged from zero in raw water samples to 950 μg/L in treated water samples. Average concentration values of THMs in primary and secondary disinfection samples exceeded the standard maximum contaminant levels. Results for the average THMs concentrations followed the order TCM > BDCM > DBCM > TBM. EPA-developed models were adopted for the estimation of chronic daily intakes (CDI) and excess cancer incidence through ingestion pathway. Higher average intake was observed in adults (4.52 × 10−2 mg/kg-day), while the ingestion in children (3.99 × 10−2 mg/kg-day) showed comparable values. The total lifetime cancer incidence rate was relatively higher in adults than children with median values 244 and 199 times the negligible risk level.

Desalinated and blended water in Saudi Arabia: human exposure and risk analysis from disinfection byproducts

Saudi Arabia produces the largest amount of desalinated water as a single country. The desalinated water is typically blended with treated groundwater, pH adjusted and chlorinated prior to supply to the communities. The desalinated seawater and/or blended water contains various types of disinfection byproducts (DBPs), some of which may induce cancer risks to human through lifetime exposure. In this study, occurrences of trihalomethanes (THMs) in desalinated and blended water in Saudi Arabia were investigated and their exposure and risks were predicted. The chronic daily intakes of CHCl 3 , BDCM, DBCM and CHBr 3 were estimated to be 8.38×10 −5 , 7.57×10 −5 , 2.54×10 −5 and 4.32×10 −4 mg/kg-day respectively. The overall cancer risk was 1.78×10 −5 with the range of 7.40×10 −7 – 9.26×10 −5 and the average hazard index was 3.49×10 −2 with the range of 1.20×10 −3 – 2.34×10 −1 . The loss of disability adjusted life years (DALY) were estimated to be 25.1 per year and the average cancer risk had 8.48×10 −7 DALY per person per year. The financial burden was estimated to be US$2.72 million with the range of US$2.52–2.91 million. The findings may assist in better understanding and reducing cancer risks from DBPs in desalinated and blended water.

Effects of plumbing systems on human exposure to disinfection byproducts in water: a case study

Disinfection byproducts (DBPs) in water distribution systems (WDS) are monitored for regulatory compliance, while populations are exposed to DBPs in tap water that may be different due to stagnation of water in plumbing pipes (PP) and heating in hot water tanks (HWT). This study investigated the effects of water stagnation in PP and HWT on exposure and risk of DBPs to humans. Trihalomethanes (THMs) in PP and HWT were observed to be 1.1-2.4 and 1.6-3.0 times, respectively, to THMs in the WDS, while haloacetic acids (HAAs) were 0.9-1.8 and 1.2-1.9 times, respectively, to HAAs in the WDS. The chronic daily intakes of DBPs from PP and HWT were 0.6-1.8 and 0.5-2.3 times the intakes from WDS. The cancer risks from PP and HWT were 1.46 (0.40-4.3) and 1.68 (0.35-5.1) times the cancer risks from WDS. The findings may assist in regulating DBPs exposure concentrations.

Toxicokinetic Modeling Of Selected Pops In Human Breast Milk Biomonitoring Study – Risk Assessment Tool

Introduction Persistent organic pollutants (POPs) are known for their harmful effects on the environment, where they can accumulate and pass through food-chains into humans. This study is focused on the risks assessment of the human health outcomes for pregnant women in the Czech Republic (1994-2009; more than 4750 samples) connected to the exposure of POPs. Samples of breast milk were collected and measured (selected POPs: PCBs, HCB, HCHs, DDT, DDE and DDD) in the biomonitoring of National Institute of Public Health in the Czech Republic. Methods The calculations of health risks were carried out using modified PBPK model. The primary route for exposure in PBPK model was assumed to be through the dietary intake and inhalation exposure. Model was reversed to predict chronic daily doses from the biological data. The final predicted doses from breast milk, in the form of chronic daily intakes (CDImilk), were compared with the intakes from Czech Dietary Exposure Monitoring (CDIfood). Results Final predicted chronic daily doses from the milk (CDImilk) were generally higher than predicted doses from the food consumption (CDIfood) (except lindane). The highest probabilistic risks were estimated for PCBs. These facts might indicate new, unknown exposure, which was discussed. Conclusions The higher levels CDImilk can indicate new / unknown / unexpected exposure (often underestimated dermal exposure, specific dietary exposure scenarios,…). The long-term data indicates decreasing trends of POPs concentrations in breast milk in Central EUROPE. New approach for Human health risk assessment by using toxicokinetic exposure reconstruction was developed.

Predicting human exposure and risk from chlorinated indoor swimming pool: a case study.

This study predicted human exposure to disinfection by-products (DBPs) in a chlorinated indoor swimming pool. Human exposure was predicted through ingestion, inhalation, and dermal routes while ingestion exposure was accidental with water intake of 18-34 mL/h. The number of pool attendants and duration and frequency of swimming were in the ranges of 14-62 persons/day, 40-85 min/event, and 26-48 times/year, respectively. Trihalomethanes (THMs) in pool water and air were 28.7-95.5 μg/L and 44.1-133.6 μg/m(3), respectively, while haloacetic acids (HAAs) in pool water were 68.9-158.9 μg/L. The brominated THMs in water and air were 95.4 and 94.3% of total THMs, respectively, while brominated HAAs were 94.4 % of total HAAs. Chronic daily intakes of THMs and HAAs were 2.16 × 10(-5)-3.14 × 10(-3) and 8.4 × 10(-8)-4.6 × 10(-6) mg/kg-day, respectively. The cancer risk from three THMs and two HAAs was 2.46 × 10(-5) with a range of 8.1 × 10(-6)-5.7 × 10(-5), in which THMs contributed 99.6% of total risks. Approximately 99.3% of risks were through inhalation and dermal routes, indicating that the ingestion route may be insignificant. The cancer risks from THMs in swimming pool were 4.06-6.64 times to the cancer risks from THMs in drinking water.

Human health risk assessment of uranium in drinking water sampled from drilled wells located in rural areas of the Lower Silesian region (Poland) / Ocena ryzyka zdrowotnego związanego z obecnością uranu w wodzie przeznaczonej do spożycia pobieranej z wierconych studni zlokalizowanych na obszarach wiejskich Dolnego Śląska (Polska)

Abstract Uranium concentrations in groundwater taken from private drilled wells have been never determined in Poland, implying a lack of available data to quantify the human exposure to U through drinking water consumption, especially in rural areas influenced by mining activities. The main aim of the study was the assessment of human health risk related to the consumption of well waters containing U, collected from selected rural areas of the Lower Silesian region (Poland). The random daytime (RDT) sampling method was applied to the collection of well waters from three control study areas (CSA): Mniszków (CSA-A), Stara Kamienica/M. Kamienica/Kopaniec (CSA-B) and Kletno (CSA-C). The analyses of RDT samples were performed by validated method based on inductively coupled plasma mass spectrometry (ICP-MS). Uranium concentration ranges in well waters and the estimated geometric means for individual control study areas were: 0.005-1.03 μg/L and 0.052 μg/L (CSA-A), 0.027-10.6 μg/L and 0.40 μg/L (CSA-B), and 0.006-27.1 μg/L and 0.38 μg/L (CSA-C). The average and individual chronic daily intakes (CDI) of U by drinking water pathway (adults/children) were in the ranges of: 0.0017-0.013/0.0052-0.040 μg · kg-1 · day-1 and 0.0002-0.90/0.0005-2.71 μg · kg-1 · day-1. The average %TDI and ranges of individual %TDI (adults/children) were: 0.17%/0.52% and 0.02-3.4%/0.05-10.3% (CSA-A), 1.3%/4.0% and 0.09-35%/0.27-106% (CSA-B), and 1.3%/3.8% and 0.02-90%/0.06-271% (CSA-C). The estimated average CDI values of U through well water are significantly lower than the TDI (1 μg · kg-1 · day-1), while for individual CDI values the contribution to the TDI can reach even 90% (adults) and 271% (children), indicating essential human health risk for children consuming well water from private drilled wells located in CSA-B and CSA-C (5.3% of total number of samples collected).

Evaluating the spatial distribution of quantitative risk and hazard level of arsenic exposure in groundwater, case study of Qorveh County, Kurdistan Iran

Regional distribution of quantitative risk and hazard levels due to arsenic poisoning in some parts of Iran’s Kurdistan province is considered. To investigate the potential risk and hazard level regarding arsenic-contaminated drinking water and further carcinogenic and non-carcinogenic effects on villagers, thirteen wells in rural areas of Qorveh County were considered for evaluation of arsenic concentration in water. Sampling campaign was performed in August 2010 and arsenic concentration was measured via the Silver Diethyldithiocarbamate method. The highest and lowest arsenic concentration are reported in Guilaklu and Qezeljakand villages with 420 and 67 μg/L, respectively. None of thirteen water samples met the maximum contaminant level issued by USEPA and Institute of Standards and Industrial Research of Iran (10 ppb). The highest arsenic concentration and consequently risk and hazard levels belong to villages situated alongside the eastern frontiers of the county. Existence of volcanic activities within the upper Miocene and Pleistocene in this part of the study area may be addressed as the main geopogenic source of arsenic pollution. Quantitative risk values are varying from 1.49E-03 in Qezeljakand to 8.92E-03 in Guilaklu and may be interpreted as very high when compared by similar studies in Iran. Regarding non-carcinogenic effects, all thirteen water samples are considered hazardous while all calculated chronic daily intakes are greater than arsenic reference dose. Such drinking water source has the potential to impose adverse carcinogenic and non-carcinogenic effects on villagers. Accordingly, an urgent decision must be made to substitute the current drinking water source with a safer one.