Novel indices reveal that pollinator exposure to pesticides varies across biological compartments and crop surroundings.

Declines in insect pollinators have been linked to a range of causative factors such as disease, loss of habitats, the quality and availability of food, and exposure to pesticides. Here, we analysed an extensive dataset generated from pesticide screening of foraging insects, pollen-nectar stores/beebread, pollen and ingested nectar across three species of bees collected at 128 European sites set in two types of crop. In this paper, we aimed to (i) derive a new index to summarise key aspects of complex pesticide exposure data and (ii) understand the links between pesticide exposures depicted by the different matrices, bee species and apple orchards versus oilseed rape crops. We found that summary indices were highly correlated with the number of pesticides detected in the related matrix but not with which pesticides were present. Matrices collected from apple orchards generally contained a higher number of pesticides (7.6 pesticides per site) than matrices from sites collected from oilseed rape crops (3.5 pesticides), with fungicides being highly represented in apple crops. A greater number of pesticides were found in pollen-nectar stores/beebread and pollen matrices compared with nectar and bee body matrices. Our results show that for a complete assessment of pollinator pesticide exposure, it is necessary to consider several different exposure routes and multiple species of bees across different agricultural systems.

Exposure study on susceptible people - SPES: An integrative biomonitoring approach.

BACKGROUND: The evaluation of environmental exposure risk requires a global analysis of pollution phenomena, including biological effects and potentially correlated clinical outcomes in susceptible populations. Although human biomonitoring plays a fundamental role in assessing the degree of contamination, it is not effective alone in identifying a direct link between exposure, biomolecular effects and outcomes on target organisms. While toxicogenomics and epidemiology are mainly focused on the investigation of molecular reactions and clinical outcomes, the monitoring of environmental matrices works independently to characterize the territorial distribution of toxic compounds, without proving any correlated health risk for residents. OBJECTIVES: We propose a new biomonitoring model based on a whole systemic analytical evaluation of environmental context. The paradigm of the method consists of identifying the sources of pollution, the migration pathways of those pollutants and their effects on target organisms. By means of this innovative, holistic epidemiological approach, we included healthy human subjects in a cohort to identify potential risks of exposure and predict possible correlated clinical outcomes. 4205 residents of the Campania region were enrolled in the "SPES" biomonitoring study, which especially focused on the areas dubbed "Land of Fires" in the recent decades. DISCUSSION: The analysis of environmental exposure risk suffers the lack of data integration from various science fields, and this comes down to a limited point of view and a limited knowledge of phenomena. In implementing our model, we first constructed an analytical picture of the Real-world situation. We next conducted a comparative risk assessment, in order to identify possible correlations between pollution and health within a holistic view. CONCLUSION: This type of research activities aims to support the implementation of public health interventions and to become a reference model in the evaluation of the risk of exposure to environmental pollutants.

Associations of total blood mercury and blood methylmercury concentrations with diabetes in adults: An exposure-response analysis of 2005-2018 NHANES.

OBJECTIVE: To examine the exposure-response relationship between mercury exposure and diabetes in adults, and to explore the possible effect modifications by selenium and omega-3 fatty acids. METHODS: Biomarker data (total blood mercury and blood methylmercury) from individuals ≥20 years of age were obtained from the 2005-2018 NHANES. Diabetes was defined through questionnaires, fasting plasma glucose, 2 -h plasma glucose and hemoglobin A1c levels. The exposure-response relationship between mercury exposure and diabetes was assessed with logistic regression and restricted cubic splines. RESULTS: Comparing the highest to lowest quartile of exposure, the multivariable-adjusted odds ratio (95 % CI) of diabetes was 0.76 (0.63-0.92) with total blood mercury and 0.82 (0.66-1.00) with blood methylmercury. The inverse associations between total blood mercury [0.55 (0.40-0.77)] and blood methylmercury [0.61 (0.38-0.97)] and diabetes were observed among individuals having higher intakes of selenium (Pfor interaction<0.05). Trends toward lower odds of diabetes with mercury exposure were mainly confined to individuals having higher intakes of omega-3 fatty acid, but the interactions were not significant. The inverse associations between total blood mercury and blood methylmercury and diabetes remained in sensitivity analyses after excluding patients with hypertension that may change their dietary intake of fish. Exposure-response analyses showed an initial decrease in odds of diabetes followed by a platform or a weaker decrease beyond 3 µg/L of total blood mercury and methylmercury concentrations, respectively. CONCLUSIONS: Total blood mercury and blood methylmercury concentrations were inversely associated with diabetes in adults, and the associations were modified by selenium.

Associations between medication use and phthalate metabolites in urine and follicular fluid among women undergoing in vitro fertilization.

BACKGROUND: Phthalates, which are used as excipients of drugs, have been related to adverse reproductive outcomes. However, the relationships between medication use and phthalate exposure among women undergoing in vitro fertilization (IVF) have not been studied. OBJECTIVE: To investigate the associations between the medication intake and phthalate metabolites in urine and follicular fluid (FF). METHOD: Eight phthalate metabolites were measured in urine and FF samples from 274 women undergoing IVF using liquid chromatography-tandem mass spectrometry. Information on recent medication intake was obtained via interview by trained staff. We constructed generalized linear regression models to examine the associations of medication intake with phthalate metabolite concentrations and dose-response relationships between the number of medicines used and metabolite concentrations in two matrices. RESULTS: Four of 10 drugs were used by more than 10% of the participants, including vitamins (23.0%), traditional Chinese medicine (TCM, 22.3%), antioxidants (12.4%) and amoxicillin (10.2%). Participants who had used TCM had 26.0% (95% CI: 0.0, 58.8%), 32.6% (95% CI: 4.2, 68.8%) and 32.3% (95% CI: 2.6, 70.6%) higher urinary mono-n-butyl phthalate (MBP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) concentrations, respectively, than those who had not. Antioxidant intake was associated with a 30.6% (95% CI: -48.5, -6.6%) decrease in the urinary MBP concentration. Compared with non-users, women who reported the use of medicines had 53.2% (95% CI: 2.7, 128.5%) higher concentrations of MMP and a 37.7% (95% CI: -60.7, -1.5%) lower level of MBP in FF, respectively. CONCLUSION: Our data suggest that the intake of some medications may increase phthalate exposure among women undergoing IVF.

Plasma titanium level is positively associated with metabolic syndrome: A survey in China's heavy metal polluted regions.

OBJECTIVE: Several heavy metals have been reported to be associated with metabolic syndrome(MetS) in general population, while effects of multiple metals exposure on MetS in residents living in heavy metal polluted regions have not been investigated. We aimed to assess the association of 23 metal levels and MetS among population living in China's heavy metal polluted regions. METHODS: From August 2016 to July 2017, a total of 2109 eligible participants were consecutively enrolled in our study in Hunan province, China. The levels of plasma and urine metals were measured by inductively coupled plasma mass spectrometer (ICP-MS). MetS was defined by the criteria of the International Diabetes Federation. Multivariable regression models were applied to analysis the potential relationship. RESULTS: In the overall population, crude model showed positive relationship of plasma titanium (Ti) with MetS and negative association of urine vanadium, iron, and selenium with MetS. After adjusted for potential confounders, only plasma Ti was positive associated with MetS (adjusted OR for Q4 versus Q1: 1.46; 95% CI: 1.06-1.99), and this positive correlation was explained by abdominal obesity (OR = 1.84, 95% CI: 1.41-2.39) and high triglycerides (OR = 2.23, 95% CI: 1.68-2.96). Further linear regression analysis revealed significant association of plasma Ti levels with waist circumference (ß = 0.0056, 95% CI: 0.0004-0.0109, P = 0.036) and triglycerides (ß = 0.0012, 95% CI: 0.0006-0.0019, P < 0.001), respectively. CONCLUSION: High plasma Ti level was associated with increased risk of MetS via increasing waist circumference and triglycerides in people under high metal exposure.

Co-exposure of serum calcium, selenium and vanadium is nonlinearly associated with increased risk of type 2 diabetes mellitus in a Chinese population.

BACKGROUND: Metals play an important role in type 2 diabetes mellitus (T2DM). This study aimed to explore the association of T2DM risk with single metal exposure and multi-metal co-exposure. METHODS: A case-control study with 223 T2DM patients and 302 controls was conducted. Serum concentrations of 19 metals were determined by inductively coupled plasma mass spectrometry (ICP-MS). Those metals with greater effects were screened out and co-exposure effects of metals were assessed by least absolute shrinkage and selection operator (LASSO) regression. RESULTS: Serum calcium (Ca), selenium (Se) and vanadium (V) were found with greater effects. Higher levels of Ca and Se were associated with increased T2DM risk (OR = 2.23, 95%CI: 1.38-3.62, Ptrend = 0.002; OR = 3.16, 95%CI: 1.82-5.50, Ptrend < 0.001), but higher V level was associated with decreased T2DM risk (OR = 0.58, 95%CI: 0.34-0.97, Ptrend < 0.001). Serum Ca and V concentrations were nonlinearly associated with T2DM risk (Poverall < 0.001, Pnonliearity < 0.001); however, Se concentration was linearly associated with T2DM risk (Poverall < 0.001, Pnonliearity = 0.389). High co-exposure score of serum Ca, Se and V was associated with increased T2DM risk (OR = 3.50, 95%CI: 2.08-5.89, Ptrend < 0.001) as a non-linear relationship (Poverall < 0.001, Pnonliearity = 0.003). CONCLUSIONS: This study suggest that higher levels of serum Ca and Se were associated with increased T2DM risk, but higher serum V level was associated with decreased T2DM risk. Moreover, co-exposure of serum Ca, Se and V was nonlinearly associated with T2DM risk, and high co-exposure score was positively associated with T2DM risk.

Children's Environmental Health: A Systems Approach for Anticipating Impacts from Chemicals.

Increasing numbers of chemicals are on the market and present in consumer products. Emerging evidence on the relationship between environmental contributions and prevalent diseases suggests associations between early-life exposure to manufactured chemicals and a wide range of children's health outcomes. Using current assessment methodologies, public health and chemical management decisionmakers face challenges in evaluating and anticipating the potential impacts of exposure to chemicals on children's health in the broader context of their physical (built and natural) and social environments. Here, we consider a systems approach to address the complexity of children's environmental health and the role of exposure to chemicals during early life, in the context of nonchemical stressors, on health outcomes. By advancing the tools for integrating this more complex information, the scope of considerations that support chemical management decisions can be extended to include holistic impacts on children's health.

Exposure contrasts associated with a liquefied petroleum gas (LPG) intervention at potential field sites for the multi-country household air pollution intervention network (HAPIN) trial in India: results from pilot phase activities in rural Tamil Nadu.

BACKGROUND: The Household Air Pollution Intervention Network (HAPIN) trial aims to assess health benefits of a liquefied petroleum gas (LPG) cookfuel and stove intervention among women and children across four low- and middle-income countries (LMICs). We measured exposure contrasts for women, achievable under alternative conditions of biomass or LPG cookfuel use, at potential HAPIN field sites in India, to aid in site selection for the main trial. METHODS: We recruited participants from potential field sites within Villupuram and Nagapattinam districts in Tamil Nadu, India, that were identified during a feasibility assessment. We performed. (i) cross-sectional measurements on women (N = 79) using either biomass or LPG as their primary cookfuel and (ii) before-and-after measurements on pregnant women (N = 41), once at baseline while using biomass fuel and twice - at 1 and 2 months - after installation of an LPG stove and free fuel intervention. We involved participants to co-design clothing and instrument stands for personal and area sampling. We measured 24 or 48-h personal exposures and kitchen and ambient concentrations of fine particulate matter (PM2.5) using gravimetric samplers. RESULTS: In the cross-sectional analysis, median (interquartile range, IQR) kitchen PM2.5 concentrations in biomass and LPG using homes were 134 µg/m3 [IQR:71-258] and 27 µg/m3 [IQR:20-47], while corresponding personal exposures were 75 µg/m3 [IQR:55-104] and 36 µg/m3 [IQR:26-46], respectively. In before-and-after analysis, median 48-h personal exposures for pregnant women were 72 µg/m3 [IQR:49-127] at baseline and 25 µg/m3 [IQR:18-35] after the LPG intervention, with a sustained reduction of 93% in mean kitchen PM2.5 concentrations and 78% in mean personal PM2.5 exposures over the 2 month intervention period. Median ambient concentrations were 23 µg/m3 [IQR:19-27). Participant feedback was critical in designing clothing and instrument stands that ensured high compliance. CONCLUSIONS: An LPG stove and fuel intervention in the candidate HAPIN trial field sites in India was deemed suitable for achieving health-relevant exposure reductions. Ambient concentrations indicated limited contributions from other sources. Study results provide critical inputs for the HAPIN trial site selection in India, while also contributing new information on HAP exposures in relation to LPG interventions and among pregnant women in LMICs. TRIAL REGISTRATION: ClinicalTrials.Gov. NCT02944682 ; Prospectively registered on October 17, 2016.

The Relationship between Annual Airborne Pollen Levels and Occurrence of All Cancers, and Lung, Stomach, Colorectal, Pancreatic and Breast Cancers: A Retrospective Study from the National Registry Database of Cancer Incidence in Japan, 1975-2015.

Suppression of risk factors including smoking, overdrinking and infections by human papilloma and hepatitis B and C viruses has been recommended for cancer prevention; however, identification of other environmental risk factors has not been enough. Besides the 2003 report that Kawasaki disease may be triggered by pollen exposure, 40 Japanese specific intractable diseases have recently been reported as "pollen diseases," also potentially triggered by pollen exposure．Various human organs are affected by pollen exposure, leading to systemic vasculitis; autoimmune connective tissue diseases, inflammatory bowel diseases and intractable neuromuscular and bone diseases, suggesting the common effects of pollen exposure on fundamental functions of vital metabolism. In this context, cancer and malignant tumors may be another group of intractable diseases triggered by epigenetic pollen exposure. Thus, this study compared the number of newly registered patients with 24 types of cancer and airborne pollen levels measured from 1975 to 2015. We searched for statistical correlations with Bonferroni correction between the annual number of newly registered patients for all cancers or for each of lung, stomach, colorectal, pancreatic and breast cancers in the patient-registry year "x", and annual airborne pollen levels measured in the same year as "x", or 1-7 years prior to the year "x". The number of newly registered patients for lung, and pancreatic cancers in the patient-registry year "x" was highly correlated with airborne pollen levels measured 2 years prior to "x". That for breast cancer was correlated with pollen levels measured 2 and 5 years prior to "x". To our knowledge, this is the first rapid communication of the association between pollen levels and cancer incidence.

Critical evaluation of human health risks due to hydraulic fracturing in natural gas and petroleum production.

The use of hydraulic fracturing (HF) to extract oil and natural gas has increased, along with intensive discussions on the associated risks to human health. Three technical processes should be differentiated when evaluating human health risks, namely (1) drilling of the borehole, (2) hydraulic stimulation, and (3) gas or oil production. During the drilling phase, emissions such as NOx, NMVOCs (non-methane volatile organic compounds) as precursors for tropospheric ozone formation, and SOx have been shown to be higher compared to the subsequent phases. In relation to hydraulic stimulation, the toxicity of frac fluids is of relevance. More than 1100 compounds have been identified as components. A trend is to use fewer, less hazardous and more biodegradable substances; however, the use of hydrocarbons, such as kerosene and diesel, is still allowed in the USA. Methane in drinking water is of low toxicological relevance but may indicate inadequate integrity of the gas well. There is a great concern regarding the contamination of ground- and surface water during the production phase. Water that flows to the surface from oil and gas wells, so-called 'produced water', represents a mixture of flow-back, the injected frac fluid returning to the surface, and the reservoir water present in natural oil and gas deposits. Among numerous hazardous compounds, produced water may contain bromide, arsenic, strontium, mercury, barium, radioactive isotopes and organic compounds, particularly benzene, toluene, ethylbenzene and xylenes (BTEX). The sewage outflow, even from specialized treatment plants, may still contain critical concentrations of barium, strontium and arsenic. Evidence suggests that the quality of groundwater and surface water may be compromised by disposal of produced water. Particularly critical is the use of produced water for watering of agricultural areas, where persistent compounds may accumulate. Air contamination can occur as a result of several HF-associated activities. In addition to BTEX, 20 HF-associated air contaminants are group 1A or 1B carcinogens according to the IARC. In the U.S., oil and gas production (including conventional production) represents the second largest source of anthropogenic methane emissions. High-quality epidemiological studies are required, especially in light of recent observations of an association between childhood leukemia and multiple myeloma in the neighborhood of oil and gas production sites. In conclusion, (1) strong evidence supports the conclusion that frac fluids can lead to local environmental contamination; (2) while changes in the chemical composition of soil, water and air are likely to occur, the increased levels are still often below threshold values for safety; (3) point source pollution due to poor maintenance of wells and pipelines can be monitored and remedied; (4) risk assessment should be based on both hazard and exposure evaluation; (5) while the concentrations of frac fluid chemicals are low, some are known carcinogens; therefore, thorough, well-designed studies are needed to assess the risk to human health with high certainty; (6) HF can represent a health risk via long-lasting contamination of soil and water, when strict safety measures are not rigorously applied.

Long-standing LPG subsidies, cooking fuel stacking, and personal exposure to air pollution in rural and peri-urban Ecuador.

Ecuador presents a unique case study for evaluating personal air pollution exposure in a middle-income country where a clean cooking fuel has been available at low cost for several decades. We measured personal PM2.5 exposure, stove use, and participant location during a 48-h monitoring period for 157 rural and peri-urban households in coastal and Andean Ecuador. While nearly all households owned a liquefied petroleum gas (LPG) stove and used it as their primary cooking fuel, one-quarter of households utilized firewood as a secondary fuel and 10% used induction stoves secondary to LPG. Stove use monitoring demonstrated clear within- and across-meal fuel stacking patterns. Firewood-owning participants had higher distributions of 48-h and 10-min PM2.5 exposure as compared with primary LPG and induction stove users, and this effect became more pronounced with firewood use during monitoring.Accounting for within-subject clustering, contemporaneous firewood stove use was associated with 101 µg/m3 higher 10-min PM2.5 exposure (95% CI: 94-108 µg/m3). LPG and induction cooking events were largely not associated with contemporaneous PM2.5 exposure. Our results suggest that firewood use is associated with average and short-term personal air pollution exposure above the WHO interim-I guideline, even when LPG is the primary cooking fuel.

Early life exposures associated with risk of small intestinal neuroendocrine tumors.

Small intestinal neuroendocrine tumors (SINT) are rare with incidence increasing over the past 40 years. The purpose of this work is to examine the role of environmental exposures in the rise of SINT incidence using the Utah Population Database, a resource of linked records including life events, cancer diagnoses and residential histories. SINT cases born in Utah were identified through the Utah Cancer Registry with: diagnosis years of 1948 to 2014 and age at diagnosis of 23 to 88 years. Controls were matched to cases 10:1 based on sex, birth year and residence time in Utah. Cases and controls were geocoded to their birth locale. An isotonic spatial scan statistic was used to test for the occurrence and location(s) of SINT clusters. Potential environmental exposures and economic conditions in the birth locales at the time of the birth (1883-1982) were generated using historical references. Conditional logistic regression was used to estimate odd ratios. We report a spatial cluster central to historic coal mining communities, associated with a 2.86 relative risk (p = 0.016) of SINT. Aspatial analyses of industry and mining exposures further suggest elevated risk for early life exposure near areas involved in the construction industry (OR 1.98 p = 0.024). Other exposures approached significance including coal, uranium and hard rock mining during the earliest period (1883-1929) when safety from exposures was not considered. We do observe a lower risk (OR 0.58 p = 0.033) associated with individuals born in rural areas in the most recent period (1945-1982). Environmental exposures early in life, especially those from industries such as mining, may confer an elevated risk of SINT.

Concentrations, Possible Sources and Health Risk of Heavy Metals in Multi-Media Environment of the Songhua River, China.

Heavy metal pollution in the river environment has been a source of widespread interest due to potential threats to human health and ecosystem security. Many studies have looked at heavy metal pollution in the context of single source-pathway-receptor relationships, however few have sought to understand pollution from a more wholistic multi-media perspective. To investigate potential risks in a more wholistic way, concentrations of six heavy metals (Cd, Cr, Ni, Cu, Zn and Pb) were detected in multi-media (water, sediment and riparian soil) collected from 14 sampling sites in the main stream of the Songhua River. Chemical analyses indicated that the average concentration of heavy metals in water followed: Zn > Cr > Cu > Pb > Ni > Cd, with a different trend observed in sediments and riparian soil: Zn > Cr > Ni > Pb > Cu > Cd. The potential risk was evaluated using the heavy metal pollution index (HPI), Nemerow pollution index (PN), hazard index (HI) and carcinogenic risk (CR) metrics. Results showed that all HPI values were lower than the critical level of 100 indicating that the levels of these targeted heavy metals were within drinking water safety limits. The PN indicated that both sediment (2.64) and soil (2.95) could be considered "moderately polluted", with Cd and Zn providing the most significant contributions. A human health risk assessment suggested that the non-carcinogenic risks were within acceptable levels (HI < 1), as was the cancer risk associated with dermal adsorption (CR <10-6). However, the CR associated with ingestion exposure (4.58 × 10-6) exceeded the cancer risk threshold (10-6) indicative of elevated cancer incidence in exposed populations. Health-risk estimates were primarily associated with Cd in the Songhua River. Source apportionment was informed by Pearson correlation analysis coupled with principal component analysis (PCA) which indicated that Cu was mainly derived from natural (geogenic) sources; Cr and Ni were associated with industrial emissions; Pb might be derived from agricultural and transportation sources; Zn might be from industrial, agricultural activities and transportation; while Cd is likely from industrial and agricultural emissions. The source apportionment information could provide the basis for a risk-management strategy focused on reducing Cd and Zn emissions to the riverine environment. Results from this study will provide the scientific knowledge that is needed for measuring and controlling heavy metals sources and pollution characteristics, and identifying the potential cancer risk with different exposure pathways, as well as making effective environmental management policies at catchment or regional scales.

Uranium in drinking water: a public health threat.

Uranium (U) has no known essential biological functions. Furthermore, it is well known for its toxicity, radioactivity, and carcinogenic potency. Impacts on human health due to U exposure have been studied extensively by many researchers. Chronic exposure to low-level U isotopes (radionuclides) may be interlinked with cancer etiology and at high exposure levels, also kidney disease. Other important issues covered U and fertilizers, and also U in soils or human tissues as an easily measurable indicator element in a pathophysiological examination. Furthermore, phosphate fertilization is known as the important source of contamination with U in the agricultural land, mainly due to contamination in the phosphate rock applied for fertilizer manufacture. Therefore, long-term usage of U-bearing fertilizers can substantially increase the concentration of U in fertilized soils. It should also be noted that U is an active redox catalyst for the reaction between DNA and H2O2. This review is aimed to highlight a series on various hydro-geochemical aspects in different water sources and focused on the comparison of different U contents in the drinking water sources and presentation of data in relation to health issues.

Health risk assessment of metal(loid)s in soil and particulate matter from industrialized regions: A multidisciplinary approach.

In this study, samples of soil and particulate matter obtained from the highly industrialized region of Ostrava, Czech Republic, are used for the toxicity evaluation of the selected metal(loid)s (Cd, Cr, Cu, Ni, Pb, Zn, As). We investigated the samples from sites supposedly affected the most by the local pollution sources using mineralogical techniques (XRD, SEM/EDS) to understand the solid speciation of the contaminants as the crucial factor affecting their release. Although the bulk composition was defined by common silicates and oxides that are rather resistant to leaching, the presence of tiny Ni, Pb, and/or Zn sulfate-like droplets indicated a potential increase of the solubility of these metals. In vitro tests simulating gastric and lung fluids were used to assess the exposure risk for humans, as well as metal(loid) bioaccessibility. Based on the results, the potential risk for the observed age group (3-year-old children) could be recognized, particularly in the cases of As, Pb and Cd for both oral and inhalation exposure. Arsenic exhibits high bioaccessibility (7.13-79.7%, with the median values of 10.6 and 15.6 for SGL and SLF, respectively), high daily intake (1.4- to 8.5-fold higher than the tolerable daily intake) and high concentrations in atmospheric PM10 (2.5 times the tolerable concentration in air). In contrast, Ni exceeded tolerable concentrations in the atmosphere up to 20-fold, but its bioaccessibility remained relatively low (0.1-22%), and Ni did not pose a major threat to human health. Cadmium, Pb and As originating from industrial activities and domestic heating have been suggested to be the most important pollutants (tolerable daily intake was exceeded by up to 74-, 34- and 8-fold for Cd, Pb and As, respectively).

Epidemiological study of kidney health in an area with high levels of soil cadmium and selenium: Does selenium protect against cadmium-induced kidney injury?

Chronic exposure to cadmium (Cd) can cause renal dysfunction. Studies of animals, cell cultures, and plants have found that selenium (Se) can effectively alleviate the hazard generated by Cd, but there has been little study of this in general human populations. This study recruited 313 subjects from China's Hubei Province, including 160 living in areas with high soil Cd and Se (exposure group) and 153 living in clean areas (control group). The levels of the following were detected: Cd and Se in blood (B-Cd and B-Se), urine (U-Cd and U-Se), and hair (H-Cd and H-Se); N-acetyl-ß-D-glucosaminidase (U-NAG), ß2-microglobulin (U-ß2-MG), and albumin (U-ALB) in urine; and malondialdehyde (S-MDA), superoxide dismutase (S-SOD), and glutathione peroxidase (S-GSH-Px) in serum. In addition, the interactions between Cd and Se were assessed. The median levels of B-Cd, B-Se, U-Cd, U-Se, H-Cd, H-Se, S-MDA, and S-GSH-Px of exposure group (2.60 ng/mL, 238.90 ng/mL, 3.13 µg/g Cr, 45.43 µg/g Cr, 0.06 µg/g, 0.70 µg/g, 5.22 nmol/mL, and 308.89 U, respectively) were significantly higher than of controls (0.95 ng/mL, 130.50 ng/mL, 1.08 µg/g Cr, 30.51 µg/g Cr, 0.04 µg/g, 0.49 µg/g, 4.71 nmol/mL, and 267.54 U, respectively), but there were no significant differences in U-NAG, U-ß2-MG, U-ALB, or S-SOD between the two groups. U-NAG levels were significantly negatively associated with the interaction between Cd and Se (B: -0.511, 95% CI: -0.886, -0.136). Additionally, changes in the direction of the estimated regression coefficient in the low and high H-Se groups were observed for U-Cd and S-MDA (from 0.018 to -0.090), U-Cd and S-GSH-Px (from -0.039 to 0.101). This study found that populations living in areas with high levels of soil Cd and Se did not show greater Cd-induced renal tubular and glomerular injuries than the control population, which could attribute to the protective effects of Se. The protective effects may be related to the peculiar function of Se that Se can combine with free Cd to activate the antioxidant enzyme system.

Residential green space and seasonal distress in a cohort of tree pollen allergy patients.

BACKGROUND: Residential green space may improve human health, for example by promoting physical activity and by reducing stress. Conversely, residential green space may increase stress by emitting aeroallergens and exacerbating allergic disease. Here we examine impacts of exposure to residential green space on distress in the susceptible subpopulation of adults sensitized to tree pollen allergens. METHODS: In a panel study of 88 tree pollen allergy patients we analyzed self-reported mental health (GHQ-12), perceived presence of allergenic trees (hazel, alder, birch) near the residence and residential green space area within 1 km distance [high (≥3 m) and low (<3 m) green]. Results were adjusted for patients' background data (gender, age, BMI, smoking status, physical activity, commuting distance, education level, allergy medication use and chronic respiratory problems) and compared with distress in the general population (N = 2467). RESULTS: Short-term distress [mean GHQ-12 score 2.1 (95% confidence interval 1.5-2.7)] was higher in the study population than in the general population [1.5 (1.4-1.7)]. Residential green space had protective effects against short-term distress [high green, per combined surface area of 10 ha: adjusted odds ratio OR = 0.94 (95% confidence interval 0.90-0.99); low green, per 10 ha: OR = 0.85 (0.78-0.93)]. However, distress was higher in patients who reported perceived presence of allergenic trees near their residence [present vs. absent: OR = 2.04 (1.36-3.07)]. CONCLUSIONS: Perceived presence of allergenic tree species in the neighbourhood of the residence of tree pollen allergy patients modulates the protective effect of residential green space against distress during the airborne tree pollen season.

Effects of personal air pollutant exposure on oxidative stress: Potential confounding by natural variation in melatonin levels.

Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) are commonly used biomarkers of oxidative stress. However, their associations with air pollutant exposure have not been consistent across studies. We hypothesize that the inconsistency is partly due to confounding of circulating melatonin. We analyzed urinary 6-sulfatoxymelatonin (aMT6s), a surrogate of circulating melatonin, along with 8-OHdG and MDA, in 159 healthy adults who had not taken melatonin supplementation. Within the natural range of endogenously-generated aMT6s (0.3-93.5 ng/mg creatinine) measured in this study, increasing aMT6s levels were significantly associated with increasing concentrations of 8-OHdG and MDA. Measurements of PM2.5, ozone (O3), and nitrogen dioxide (NO2), coupled with time-activity data, were used to calculate time-averaged personal exposures 12 -hour (12h) and 24-hour (24h) prior to urine collection. Without controlling for aMT6s, the relationships between pollutant exposure and 8-OHdG or MDA were not clear. After controlling for aMT6s, an interquartile range (IQR) increase in 12h PM2.5 and 12h NO2 exposure was associated with 6.1% [95%CI: 1.6%-10.8%] and 8.6% [1.3%-16.5%] increase in MDA, respectively. An IQR increase in 12h O3 exposure was associated with a 5.7% [1.9%-9.7%] in 8-OHdG. The findings suggest the need for controlling for aMT6s as a confounder in using urinary 8-OHdG and MDA as biomarkers of oxidative stress related to short-term air pollution exposure.

Contamination by As, Hg, and Sb in a region with geogenic As anomaly and subsequent human health risk characterization.

Arsenic (As) is among the most harmful toxic elements to human health with severe carcinogenic and non-carcinogenic effects. The present study aims to (1) characterize a site with geogenic As anomaly (Emet basin) in Kutahya, Turkey via soil (urban, agriculture, forest; n = 53 total), water (n = 11), and agricultural product (n = 19) samples; and, (2) characterize human health risks for different receptors under specific exposure scenarios. Soil As levels were very high (range, 22.4-765 mg kg-1). Previous literature suggested some evidence of Sb and Hg combined with As in mineral forms in the region; the present study found elevated Sb (up to 76.0 mg kg-1) in two regions with very high As levels, but Hg concentrations were low in the region. Soils from urban/agricultural zones (representing anthropogenic impact) did not have statistically different As levels compared with forest soils (representing low/no human impact). As water concentrations were also very high (range, 14.0-729 µg L-1), however, uptake by agricultural products was low, mostly limited to wheat (up to 0.7 mg kg-1). Exposure assessment/risk characterization showed that non-carcinogenic risk following exposure to soils was very high for children (hazard index up to 37 under reasonable maximum exposure) as well as carcinogenic risk (probability up to 1.19E-3). The risk was even higher considering intake of water, and in this case, both for children and adults (HI, 4.0-66.6; cancer risk, 1.29E-4-1.84E-2). The potential adverse outcomes of the As anomaly in the region may be grave, thus further geochemical investigation of As speciation and mobile fractions as well as gastrointestinal As bioaccessibility supplementing probabilistic human health risk characterization are recommended.

Toenails as biomarker of exposure to essential trace metals: A review.

Health problems associated with essential trace metals can result from both inadequate (i.e., low intake) and excessive exposures (i.e., from environmental and/or occupational source). Thus, measuring the exposure level is a real challenge for epidemiologists. Among non-invasive biomarkers that intend to measure long-term exposure to essential trace metals, the toenail is probably the biological matrix with the greatest potential. This systematic review collects the current evidence regarding the validity of toenail clippings as exposure biomarker for trace metals such as boron, cobalt, copper, iron, manganese, molybdenum, selenium, silicon, vanadium and zinc. Special attention was paid to the time-window of exposure reflected by the toenail, the intraindividual variability in exposure levels over time in this matrix, and the relationship of toenail with other biomarkers, personal characteristics and environmental sources. Our search identified 139 papers, with selenium and zinc being the most studied elements. The variability among studies suggests that toenail levels may reflect different degrees of exposure and probably correspond to exposures occurred 3-12 months before sampling (i.e., for manganese/selenium). Few studies assessed the reproducibility of results over time and, for samples obtained 1-6 years apart, the correlation coefficient were between 0.26 and 0.66. Trace metal levels in toenails did not correlate well with those in the blood and urine and showed low-moderate correlation with those in the hair and fingernails. Available data suggests that for some elements (Se, Mn, Zn) toenail concentrations reflect long-term external exposures in fairly reproducible levels, while for other metals, this association has not yet been assessed. Among dietary factors, only toenail selenium showed clear associations with the intake of supplements or specific foods. The toenail levels could also represent occupational exposure, for instance, Mn exposure in welders. The scarcity of information on other essential trace elements, together with the great heterogeneity among studies makes the validation of the usage of toenails as biomarkers of exposure to these elements difficult. Standardization of sample collection, quality control, analytical techniques and reporting procedures might facilitate further research focused on the clear understanding of the significance of essential levels in this promising matrix and would enhance its utility in epidemiological research.