Urinary metabolite levels of pyrethroid insecticides in infants living in an agricultural area of the Province of Jiangsu in China

Pyrethroid insecticides are extensively and increasingly applied in agricultural and residential environments in China. Children’s exposure to pesticides attracted global concerns because of their particular vulnerability. Several studies have reported residual pyrethroid levels in urine both in adults and in children. However, few published data focused on very young infants. The study aimed to assess exposure to pyrethroid insecticides in young infants and investigate the potential influence factors on pyrethroid exposure levels. Data on pyrethroids exposure was based on questionnaire items and measurement of urinary metabolite levels among 481 infants. We detected pyrethroid metabolites of 3-phenoxybenzoic acid (3-PBA), cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-DCCA and trans-DCCA) in urine using a gas chromatography-mass spectrometry method. Median values for urinary pyrethroid metabolites in these infants were 0.39 μg L^?1 for 3-PBA, 0.18 μg L^?1 for cis-DCCA, 0.92 μg L^?1 for trans-DCCA, respectively. About 60.9% of the infants had urinary concentrations of three pyrethroid metabolites that were above the level of 0.10 μg L^?1 (limit of detection, LOD). These findings of the urinary metabolites were comparable or slightly higher than those children from the other countries. From questionnaire, we learned that more than 70% of households reported that they or family members had applied mosquito repellents in infants. Above data indicated the need to assess the potential adverse effects of pyrethroids exposure on infants in order to take adequate measures to protect them from pesticide exposures during early childhood.     

The relationship of 3-PBA pyrethroids metabolite and male reproductive hormones among non-occupational exposure males

Many pesticides possess hormonal activities and have been classified as endocrine disrupting chemicals. Synthetic pyrethroids are one kind of the most common pesticides used in the world. In the present study, we explored the association between serum reproductive hormone levels and urinary creatine (CR) adjusted concentration of 3-phenoxybenzoic acid (3-PBA), a general metabolite of pyrethroids, in Chinese adult men. The study subjects (n=212) were from the affiliated hospitals of Nanjing Medical University. By using GC-MS, urinary 3-PBA level of each subject was measured and adjusted by urinary CR. Blood samples were collected for measuring the serum levels of reproductive hormones, including follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), testosterone (T) and prolactin (PRL). All the subjects had detectable levels of 3-PBA in their urine samples. The median concentration of 3-PBA was 0.815 microg g (-1)of CR. The results showed that there was positive associations between the levels of serum LH and 3-PBA (p=0.013) but negative associations between E2 and 3-PBA level (p=0.022), and the adjusting p-value was 0.044 for LH and E2, which suggested that pyrethroids are capable of disrupting the male endocrine function. In adult men, urinary 3-PBA levels were associated with increased LH and reduced E2 levels. On a population level, these reductions show potential public health importance because of widespread exposure to these pesticides.     

Antiandrogenic activity of pyrethroid pesticides and their metabolite in reporter gene assay

Many pesticides possess hormonal activity and have thus been classified as endocrine disruptors. Pyrethroids are commonly used pesticides worldwide, but little has been done to characterize their antiandrogenic activity potential. We tested three frequently encountered pyrethroids (fenvalerate, cypermethrin, permethrin) and their metabolite 3-phenoxybenzoic acid (3-PBA) for antiandrogenic and androgenic activity using a human androgen receptor (AR) mediated luciferase reporter gene assay in CV-1 African green monkey kidney cell. The assay displayed appropriate response to the known AR agonist 5alpha-dihydrotestosterone and AR antagonist nilutamide and flutamide. At 0.1mM, all the three tested pyrethroids significantly suppressed the luciferase expression. Further, their metabolite 3-PBA also showed antagonist activity. None of the test chemicals showed androgenic activity. Through the antiandrogenic pathways, exposure to certain pyrethroids may contribute to the damage of reproductive system. In conclusion, pyrethroid pesticides can act as antiandrogen in vitro, and metabolizing to 3-PBA cannot eliminate the antagonist activity. This result provides useful information for risk assessment of pyrethroid pesticides.     

Biomonitoring of pyrethroid exposure among rural and urban populations in northern Poland

The aim of this study was to determine for the first time in Poland, levels of exposure to synthetic pyrethroids in preschool and school age children and their parents living in urban and rural areas. For this purpose concentrations of pyrethroid metabolites: 3-phenoxybenzoic acid (3-PBA), 2,2-dibromovinyl-2,2-dimethylcyclopropanecarboxylic acid (Br₂CA), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Cl₂CA) and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (trans-Cl₂CA) were determined in 374 urine samples using a validated GC–MS method.     

Simultaneous determination of eight metabolites of organophosphate and pyrethroid pesticides in urine

A simultaneous method for quantifying eight metabolites of organophosphate pesticides and pyrethroid pesticides in urine samples has been established. The analytes were extracted using liquid–liquid extraction coupled with WCX solid phase extraction (SPE) cartridges. Eight metabolites were chemically derivatized before analysis using gas chromatography–tandem mass spectrometry (GC–MS–MS). The separation was performed on a HP-5MS capillary column (30 m × 0.25 mm × 0.25 µm) with temperature programming. The detection was performed under electro-spray ionization (ESI) in multiple reaction monitoring (MRM) mode. An internal standard method was used. The extraction solvent, types of SPE cartridges and eluents were optimized by comparing the sample recoveries under different conditions. The results showed that the calibration curves of the five organophosphorus pesticides metabolites were linear in the range of 0.2–200 μg/L (r² ≥ 0.992) and that of the three pyrethroid pesticides metabolites were linear in the range of 0.025–250 μg/L (r² ≥ 0.991). The limits of detection (LODs, S/N ≥ 3) and the limits of quantification (LOQs, S/N ≥ 10) of the eight metabolites were 0.008–0.833 μg/L and 0.25–2.5 μg/L, respectively. The recoveries of the eight metabolites ranged from 54.08% to 82.49%. This efficient, stable, and cost-effective method is adequate to handle the large number of samples required for surveying the exposure level of organophosphorus and pyrethroid pesticides in the general population.     

The interaction effects of FEN1 rs174538 polymorphism and polycyclic aromatic hydrocarbon exposure on damage in exon 19 and 21 of EGFR gene in coke oven workers

Polycyclic aromatic hydrocarbon (PAH) exposure and genetic susceptibility were conductive to genotoxic effects including gene damage, which can increase mutational probability. We aimed to explore the dose-effect associations of PAH exposure with damage of exons of epidermal growth factor receptor (EGFR) and breast cancer susceptibility gene 1 (BRCA1), as well as their associations whether modified by Flap endonuclease 1 (FEN1) genotype. Two hundred eighty-eight coke oven male workers were recruited, and we detected the concentration of 1-hydroxypyrene (1-OH-pyr) as PAH exposure biomarker in urine and examined base modification in exons of EGFR and BRCA1 respectively, and genotyped FEN1 rs174538 polymorphism in plasma. We found that the damage indexes of exon 19 and 21 of EGFR (EGFR-19 and EGFR-21) were both significantly associated with increased urinary 1-OH-pyr (both P_trend < 0.001). The levels of urinary 1-OH-pyr were both significantly associated with increased EGFR-19 and EGFR-21 in both smokers and nonsmokers (both P < 0.001). Additionally, we observed that the urinary 1-OH-pyr concentrations were linearly associated with both EGFR-19 and EGFR-21 only in rs174538 GA+AA genotype carriers (both P < 0.001). Moreover, FEN1rs rs174538 showed modifying effects on the associations of urinary 1-OH-pyr with EGFR-19 and EGFR-21 (both P_interaction < 0.05). Our findings revealed the linear dose-effect association between exon damage of EGFR and PAH exposure and highlight differences in genetic contributions to exon damage and have the potential to identify at-risk subpopulations who are susceptible to adverse health effects induced by PAH exposure.

     

Relation of dietary inorganic arsenic exposure and urinary inorganic arsenic metabolites excretion in Japanese subjects

Inorganic arsenic (InAs) is a ubiquitous metalloid that has been shown to exert multiple adverse health outcomes. Urinary InAs and its metabolite concentration has been used as a biomarker of arsenic (As) exposure in some epidemiological studies, however, quantitative relationship between daily InAs exposure and urinary InAs metabolites concentration has not been well characterized. We collected a set of 24-h duplicated diet and spot urine sample of the next morning of diet sampling from 20 male and 19 female subjects in Japan from August 2011 to October 2012. Concentrations of As species in duplicated diet and urine samples were determined by using liquid chromatography-ICP mass spectrometry with a hydride generation system. Sum of the concentrations of urinary InAs and methylarsonic acid (MMA) was used as a measure of InAs exposure. Daily dietary InAs exposure was estimated to be 0.087 µg kg^?1 day^?1 (Geometric mean, GM), and GM of urinary InAs+MMA concentrations was 3.5 ng mL^?1. Analysis of covariance did not find gender-difference in regression coefficients as significant (P > 0.05). Regression equation Log ₁₀ [urinary InAs+MMA concentration] = 0.570× Log ₁₀ [dietary InAs exposure level per body weight] + 1.15 was obtained for whole data set. This equation would be valuable in converting urinary InAs concentration to daily InAs exposure, which will be important information in risk assessment.     

Sex-specific differences in early renal impairment associated with arsenic,lead, and cadmium exposure among young adults in Taiwan

Exposure to a single metal has been reported to damage renal function in humans. However, information regarding the association between multiple-metal exposure and markers for early renal impairment in different sexes among the young adult Taiwanese population is scarce. We assessed the association between exposure to arsenic (As), cadmium (Cd), and lead (Pb), and early renal impairment markers using urinary microalbumin (MA), β2-microglobulin (β2MG), and N-acetyl-beta-D-glucosaminidase (NAG) by analyzing 157 young adults aged 20?29 years, in Taiwan. Inductively coupled plasma mass spectrometry was used to determine urinary As, Cd, and Pb levels. Regression models were applied to different sex groups. The results showed that after adjusting for potential confounding factors and each metal, urinary Cd levels were significantly positively associated with urinary MA (β?=?0.523, 95% CI: 0.147–0.899) and β2MG (β?=?1.502, 95% CI: 0.635–2.370) in males. However, the urinary Cd level was significantly positively associated with only urinary NAG (β?=?0.161, 95% CI: 0.027–0.296) in females. This study thus indicates that the effect of exposure to metals (especially Cd) on early renal impairment among young adults in Taiwan is sex-specific. Our study results could contribute toward developing early intervention programs for decreasing the incidence of renal dysfunction. Further studies are warranted to confirm our findings and clarify the potential mechanisms involved.

     

The current status of osteoporosis after 15 years of reduced cadmium exposure among residents living in cadmium-contaminated areas in northwestern Thailand

The purposes of this study were to determine the prevalence of osteoporosis after 15 years of reduced cadmium exposure and to determine the association between urinary cadmium (U-Cd) and osteoporosis. The study was conducted with 937 participants (109 males, 828 females) living in a cadmium-contaminated area in northwestern Thailand. All participants were required to respond to a questionnaire. Bone mineral density (BMD) was investigated by measurements taken at the calcaneus by dual-energy X-ray absorptiometry. U-Cd, which reflects the amount of cadmium contained in the body, was measured by atomic absorption spectrophotometry (AAS). The geometric mean of U-Cd was significantly higher in males than in females (p < 0.001). The mean level of BMD for females was found to be statistically significantly lower than that for males (p < 0.001). Increasing U-Cd levels were correlated with decreasing levels of BMD. The association between U-Cd and osteoporosis appeared to exist only at concentrations of U-Cd ≥ 10 μg/g creatinine (OR = 2.7, 95% CI = 1.2–5.9). It can be concluded that despite discontinued or reduced cadmium exposure for more than 10 years, the effect of cadmium toxicity on bone, which is stronger in women, continues, as cadmium, once absorbed, will accumulate in the human body for a long time due to its extremely long half-life.

     

Mercury in dental amalgam: Are our health care workers at risk?

Dental amalgam in fillings exposes workers to mercury. The exposure to mercury was investigated among 1871 dental health care workers. The aim of the study was to evaluate the risk of mercury exposure among dental compared to nondental health care workers and to determine other risk factors for mercury exposure. Respondents answered questionnaires to obtain demographic, personal, professional, and workplace information and were examined for their own amalgam fillings. Chronic mercury exposure was assessed through urinary mercury levels. In total, 1409 dental and 462 nondental health care workers participated in the study. Median urine mercury levels for dental and nondental health care workers were 2.75 μg/L (interquartile range [IQR] = 3.0175) and 2.66 μg/L (IQR = 3.04) respectively. For mercury exposure, there were no significant risk factor found among the workers involved within the dental care. The Mann–Whitney test showed that urine mercury levels were significantly different between respondents who eat seafood more than 5 times per week compared to those who eat it less frequently or not at all (p = 0.003). The urinary mercury levels indicated significant difference between dental workers in their practice using squeeze cloths (Mann–Whitney test, p = 0.03). Multiple logistic regression showed that only the usage of cosmetic products that might contain mercury was found to be significantly associated with the urinary mercury levels (odds ratio [OR] = 15.237; CI: 3.612–64.276). Therefore, mean urinary mercury levels of health care workers were low. Exposure to dental amalgam is not associated with high mercury exposure. However, usage of cosmetic products containing mercury and high seafood consumption may lead to the increase of exposure to mercury.

Implications: Exposure to the high levels of mercury from dental amalgam can lead to serious health effects among the dental health care workers. Nationwide chronic mercury exposure among dental personnel was assessed through urinary mercury levels. Findings suggest low urinary mercury levels of these health care workers. Exposure to dental amalgam is not associated with high mercury exposure. However, the usage of cosmetic products containing mercury and high seafood consumption may lead to the increase of exposure to mercury.     

Association of exposure to multiple metals with papillary thyroid cancer risk in China

Papillary thyroid cancer (PTC) has inflicted huge threats to the health of mankind. Metal pollution could be a potential risk factor of PTC occurrence, but existing relevant epidemiological researches are limited. The current case-control study was designed to evaluate the relationships between exposure to multiple metals and the risk of PTC. A total of 262 histologically confirmed PTC cases were recruited. Age- and gender-matched controls were enrolled at the same time. Urine samples were used as biomarkers to reflect the levels of environmental exposure to 13 metals. Conditional logistic regression models were adopted to assess the potential association. Single-metal and multi-metal models were separately conducted to evaluate the impacts of single and co-exposure to 13 metals. The increased concentration of urinary Cd, Cu, Fe, and Pb quartiles was found significant correlated with PTC risk. We also found the decreased trends of urinary Se, Zn, and Mn quartiles with the ORs for PTC. These dose-response associations between Pb and PTC were observed in the single-metal model and remained significant in the multi-metal model (OR_25-50th=1.39, OR_50-75th=3.32, OR_>75th=7.62, p for trend <0.001). Our study suggested that PTC was positively associated with urinary levels of Cd, Cu, Fe, Pb, and inversely associated with Se, Zn, and Mn. Targeted public health policies should be made to improve the environment and the recognition of potential risk factors. These findings need additional studies to confirm in other population.

     

Cross-sectional biomonitoring study of pesticide exposures in Queensland,Australia, using pooled urine samples

A range of pesticides are available in Australia for use in agricultural and domestic settings to control pests, including organophosphate and pyrethroid insecticides, herbicides, and insect repellents, such as N,N-diethyl-meta-toluamide (DEET). The aim of this study was to provide a cost-effective preliminary assessment of background exposure to a range of pesticides among a convenience sample of Australian residents. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n = 24 pools of 100 specimens). Concentrations of urinary pesticide biomarkers were quantified using solid-phase extraction coupled with isotope dilution high-performance liquid chromatography–tandem mass spectrometry. Geometric mean biomarker concentrations ranged from <0.1 to 36.8 ng/mL for organophosphate insecticides, <0.1 to 5.5 ng/mL for pyrethroid insecticides, and <0.1 to 8.51 ng/mL for all other biomarkers with the exception of the DEET metabolite 3-diethylcarbamoyl benzoic acid (4.23 to 850 ng/mL). We observed no association between age and concentration for most biomarkers measured but noted a “U-shaped” trend for five organophosphate metabolites, with the highest concentrations observed in the youngest and oldest age strata, perhaps related to age-specific differences in behavior or physiology. The fact that concentrations of specific and non-specific metabolites of the organophosphate insecticide chlorpyrifos were higher than reported in USA and Canada may relate to differences in registered applications among countries. Additional biomonitoring programs of the general population and focusing on vulnerable populations would improve the exposure assessment and the monitoring of temporal exposure trends as usage patterns of pesticide products in Australia change over time.     

Blood nickel and chromium levels in association with smoking and occupational exposure among head and neck cancer patients in Tunisia

Chronic exposure to chromium (Cr) and nickel (Ni) has long been recognized as being capable to increase head and neck cancer (HNC) incidence among exposed human populations. This study represents the first biomonitoring of Cr and Ni exposure in Tunisia and focuses on a possible association with HNC risk. The aim of the present study was to evaluate the concentrations of Cr and Ni in the blood of HNC patients and controls. Metals blood levels of 169 HNC patients and 351 controls were determined using a Perkin-Elmer Analyst 800 Atomic Absorption Spectrometer. Mean blood levels of Cr and Ni in HNC cases (52.15 and 111.60 μg/L, respectively) were significantly higher than those of controls (37.04 and 30.50 μg/L, respectively). Cases’ blood levels of Cr and Ni were significantly higher than those of controls after controlling for the other risk factors of HNC, including smoking, shisha consumption, occupational exposure, and nearby environment (P?<?0.05). Among these risk factors, smoking and occupational exposure presented the most significant association with HNC (odds ratio (OR)?=?6.54 and 7.66, respectively, P?<?0.001). Cr and Ni levels in blood sample of cases and controls that are smoker/occupationally exposed were higher than that of non-smoker/non-occupationally exposed (P?<?0.05). Smokers who are occupationally exposed present the most significant association with HNC (OR?=?25.08, P?<?0.0001). High levels of blood Cr (OR?=?2.09) and high levels of blood Ni (OR?=?8.87) were strongly associated with HNC after other potential confounders were controlled (P?=?0.004 and P?<?0.0001, respectively). This study suggested a potential role of Cr and Ni in the mechanism of HNC development.     

Association between the nickel exposure and lipid profiles in general population from NHANES

This study is to investigate the association between nickel exposure and serum lipid profiles. We analyzed the population from the National Health and Nutrition Examination Surveys (NHANES) 2017–2018. Urinary nickel exposure was measured using inductively coupled-plasma mass spectrometry. Serum lipid profiles, including triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C), were measured using the standard biochemistry assays. The association between urinary nickel and lipid profiles was examined using multivariable linear regression models and restricted cubic spine plots. There was a significant negative relationship between nickel level and TC (β,???9.67; 95% CI,???13.58 to???5.76), HDL-C (β,???1.57; 95% CI,???2.98 to???0.16), and LDL-C (β,???5.88; 95% CI,???11.04 to???0.71) after adjusting for potential confounding factors. Furthermore, restricted cubic spines showed that only HDL-C was nonlinearly associated with nickel (p for nonlinearity 0.004). However, nickel exposure was not related to the level of triglyceride. The exposure to nickel was linearly associated with serum total cholesterol and LDL-C while nonlinearly associated with HDL-C in general population.

     

The response of Chenopodium album L. and Abutilon theophrasti Medik. to reduced doses of mesotrione

Limited toxicity data are available for estuarine and marine species and the widely used pyrethroid insecticide, permethrin. This study determined acute effects of permethrin on survival, lipid peroxidation, acetylcholinesterase activity, and splenocyte proliferation for two fish species found in South Carolina estuaries; juvenile red drum (Sciaenops ocellatus) and adult mummichog (Fundulus heteroclitus). Juvenile S. ocellatus were significantly more sensitive than adult F. heteroclitus to permethrin exposure, with a 96-h LC50 value of 8 μg/L determined for red drum compared to 23 μg/L for mummichog. Lipid peroxidation activity of the liver increased in permethrin-treated fish compared to control animals after 24 h and decreased after 96 h. Permethrin had no effect on acetylcholinesterase activity of the brain at the concentrations tested. Permethrin exposure significantly inhibited splenocyte proliferation, indicating an immunosuppressive effect. Most of the effects of permethrin on fish cellular stress enzymes and survival occurred at concentrations much higher than those typically measured in the environment. However, inhibition of splenocyte proliferation in juvenile red drum occurred at approximately twice that of measured permethrin concentrations in surface water. These findings may prove useful to the future management and regulation of pyrethroid insecticide use near estuarine habitats.     

Considering the effects of ambient particulate matter on the lung function of motorcycle taxi drivers in Bangkok,Thailand

The motorcycle taxi drivers of Bangkok have been heavily exposed to high concentrations of PM₁₀ (particulate matter with an aerodynamic diameter ≤10 μm), and the impact of this on their lungs has been neither documented nor studied. This study examines the association between exposure to PM₁₀ and lung function decline among motorcycle taxi drivers. A cross-sectional study was conducted in Bangkok between two groups: a subject group of motorcycle taxi drivers and control group of enclosed vehicle taxi drivers. The findings of the Thailand Pollution Control Department were used to estimate the annual ambient PM₁₀ concentration levels in the metropolis. Pulmonary functions of motorcycle taxi drivers and enclosed vehicle taxi drivers were measured and compared using the Mann-Whitney test. Multiple linear regression analysis was applied to estimate the effects of PM₁₀ exposure on the lung function of motorcycle taxi drivers. A total of 1283 motorcycle taxi drivers and 600 taxi drivers were investigated. The mean forced expiratory volume in 1 sec/forced vital capacity (FEV₁/FVC) of the motorcycle taxi drivers was significantly lower than that of the taxi drivers (P < 0.001). The mean FEV₁/FVC of motorcycle taxi drivers exposed to ≥50 µg/m³ PM₁₀ was statistically lower (?2.82%; 95% confidence interval [CI]: ?4.54% to ?1.09%) and the mean % vital capacity (%VC) of those exposed to 40–49.9 µg/m³ PM₁₀ was statistically lower than that of motorcycle taxi drivers exposed to <30 µg/m³ PM₁₀ (?3.33%; 95% CI: ?5.79% to ?0.87%). Motorcycle taxi drivers were directly exposed to air pollution in their working environment. As a result, their lung function might decrease more than that of enclosed vehicle taxi drivers. With the possible exposure to ≥50 µg/m³ PM₁₀, the vehicular emission standards should be vigorously enforced. Further investigation is warranted to clarify the effect of lung dysfunction on the work and lifestyle of motorcycle taxi drivers.

Implications: Motorcycle taxi drivers are directly exposed to air pollution in their work environment; therefore, their lung function might decrease more than that of enclosed vehicle taxi drivers, especially when exposed to ≥50 µg/m³ PM₁₀. World Health Organization (WHO) vehicular emission standards should be recognized and eventually enforced.     

The association between environmental cadmium exposure,blood pressure,and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were???0.795 and???1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

     

Associations between co-exposure to multiple metals and renal function: a cross-sectional study in Guangxi,China

The association between co-exposure to multiple metals and renal function is poorly understood. We aimed to evaluate the individual and joint effects of metal exposure on renal function in this study. We performed a cross-sectional study including 5828 participants in Guangxi, China, in 2019. Urine concentrations of 17 metals were detected by inductively coupled plasma mass spectrometry (ICP-MS). Logistic regression model and restricted cubic spline (RCS) were applied to investigate the association of individual metal exposure with renal dysfunction. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were used to assess the co-exposure effects of the metals. Participants with the highest quartile of urinary Cu were at 1.84-fold (95% confidence interval (CI): 1.20–2.87) increased risk of renal dysfunction compared with the lowest quartile. The highest quartiles of urinary Sr, Cs, V, Ba, and Se were associated with 0.27-fold (95% CI: 0.17–0.43), 0.33 (95% CI: 0.19–0.53), 0.41 (95% CI: 0.25–0.65), 0.58 (95% CI: 0.36–0.90), and 0.33 (95% CI: 0.19–0.56) decreased risk of renal dysfunction compared with their lowest quartile, respectively. Furthermore, urinary Ba and Cu were non-linearly correlated with renal dysfunction. The WQS analysis showed that mixed metal exposure was inversely associated with renal dysfunction (OR = 0.47, 95% CI: 0.35–0.62), and Sr accounted for the largest weight (52.2%), followed by Cs (32.3%) in the association. Moreover, we observed a potential interaction between Cu, Cs, and Ba for renal dysfunction in BKMR model. Exposure to Se, Sr, Cs, V, and Ba is associated with decreased risk of renal dysfunction, whereas an increased risk is associated with Cu exposure. Co-exposure to these metals is negatively associated with renal dysfunction, and Sr and Cs are the main contributors to the associations.

     

Low-level arsenic exposure is associated with bladder cancer risk and cigarette smoking: a case–control study among men in Tunisia

Although exposure to high levels of arsenic is associated with excess bladder cancer risk, lower exposures generally are not. This study represents the first biomonitoring of arsenic exposure in Tunisia and focuses on a possible association with bladder cancer risk. In this context, 124 male bladder cancer cases and 220 controls were recruited and blood samples were analyzed to determine the concentration of As. The study subjects were stratified into median groups based on concentrations of arsenic in their blood. Blood arsenic (B-As) was significantly two to threefold higher in bladder cancer cases than in controls (p?<?0.05). The arsenic concentrations were significantly higher among both smokers and workers in construction. However, neither drinking water nor seafood was found to be incriminated as exposure sources. The adjusted risk ratios for B-As concentration categories 0.1–0.67 and ≥0.67 μg/L were 0.18 (95% CI?=?0.014–2.95) and 2.44 (95% CI?=?1.11–5.35), respectively. Arsenic levels were not found to be associated with tumor grade or stage. The considerable risk in the category of highest cumulative exposure argues for an association between bladder cancer risk and low-level arsenic exposure. Future investigations with larger samples and using techniques that allow the distinction of the different arsenic species should better elucidate this association. Furthermore, the modulation of arsenic level according to the histological grade may be of potential to be used as a diagnostic marker of the disease process and its possible relationship etiologically.     

Association of human cohorts exposed to blood and urinary biomarkers of PAHs with adult asthma in a South Asian metropolitan city

Semi-volatile organic compounds (SVOCs) are a major global problem that causes the greatest impact on urban settings and have been linked to bronchial asthma in both children and adults in Pakistan. The association between exposure of polycyclic aromatic hydrocarbons (PAHs) and asthma in the adult population is less clear. The current study aimed to assess the clinico-chemical parameters and blood levels of naphthalene phenanthrene, pyrene, and 1,2-benzanthracene and urinary levels of 1-OH pyrene and 1-OH phenanthrene as well as asthma-related biomarkers immunoglobulin E (IgE), resistin, and superoxide dismutase (SOD) of oxidative stress and other hematologic parameters in adults and their relationship with bronchial asthma. The GC/MS analysis showed higher mean concentrations of blood PAHs in asthma respondents (4.48 ± 1.34, 3.46 ± 1.04, 0.10 ± 0.03, and 0.29 ± 0.09) (ng/mL) as compared to controls (3.07 ± 0.92, 1.71 ± 0.51, 0.06 ± 0.02, and 0.11 ± 0.03) (ng/mL), with p = .006, p = .001, p = .050, and p = .001. Similarly, urinary levels of 1-OHpyr and 1-OHphe were significantly increased in adults with bronchial asthma (0.54 ± 0.16; 0.13 ± 0.04) (μmol/mol-Cr) than in controls (0.30 ± 0.09; 0.05 ± 0.02) (μmol/mol-Cr), with p = .002 and p = .0001, respectively, with a significant positive correlation to asthma severity. The asthma-related biomarkers IgE, resistin, and SOD were significantly higher (p 0.0001, 0.0001, and 0.0001) in people with asthma than in control persons. The findings showed that higher blood and urine PAHs levels were linked to higher asthma risk in adults and significant interaction with participants who smoked, had allergies, had a family history of asthma, and were exposed to dust. The current study’s findings will be useful to local regulatory agencies in Lahore in terms of managing exposure and advocating efforts to minimize PAH pollution and manage health.