Human biomonitoring of novel brominated flame retardants:A review on invasive and non-invasive biomarkers

Novel brominated flame retardants(NBFRs)are a group of chemicals applied mainly as alternatives to the phased-out polybrominated diphenyl ethers(PBDEs).However,toxicological studies show that NBFRs may pose health risks similar to PBDEs.The present study reviews available information on the biomonitoring of NBFRs and their metabolites in humans through invasive and non-invasive biomarkers,as well as the toxicological effects of these chemicals both in vivo and in vitro.In general,higher concentrations of NBFRs were reported in tissues of occupationally exposed adults from NBFR production facilities,e-waste recycling facilities and inhabitants living close to these areas,compared to the general population.It is worth noting that NBFR human biomonitoring data are limited to few countries located in North America,Europe and Asia,while data from developing countries are scarce.Evidence from in vivo and in vitro toxicity studies show that several NBFRs can cause adverse health effects through various modes of action,mainly:hormone disruption,genotoxicity,endocrine disruption,and behavioural changes.Although few studies have investigated the biotransformation of NBFRs in humans,evidence suggests that the toxicity of some NBFRs may be augmented through their metabolites,as in the case of 2,3,4,5-tetrabromobenzoic acid(TBBA),which may exhibit higher toxicity than its parent compound 2-ethylhexyl-2,3,4,5-tetrabromobenzoate(EH-TBB).More research is required to assess toxicity thresholds,toxic endpoints,and tolerable intakes for various NBFRs,and their metabolites in human.Comprehensive epidemiological studies are highly recommended to further understand the risk arising from human exposure to different NBFRs,particularly in occupational settings.

Biomonitoring of endosulfan toxicity in human

Chemicals are comprehensively used worldwide to control herbs,weeds,pests,and other competing agents with various growing crops.The consumption of crops grown with these chemicals(even in small quantities)can upshot into accumulation in the human body.People can accidentally inhale these hazardous chemicals if they are in an area where they were applied.These chemicals can be ingested in a human with contaminated food and drinks.Ultimately it causes various adverse effects(chronic toxicity,teratogenic,mutagenic,carcinogenic effect,reproductive,and organ toxicity)on human health.Among the pool of these chemicals used as pesticides in the environment,exposure of endosulfan to humans has a potential health risk throughout the globe.The poisoning of endosulfan is reported frequently in society,therefore,this article highlights the toxicological and other harmful properties of endosulfan to humans and emphasized its essential biomonitoring.Its quick monitoring and effective hazard evaluation are possible with multiomics technologies and some other analytical approaches.This review summarizes the introduction and mechanism of action of endosulfan along with some other toxic chemicals used in the agriculture work,the toxicity of endosulfan in human/environment,and importantly its biomonitoring(detection of chemicals and their metabolites in a biological sample)in human because biomonitoring is often considered as the most preferred method.Biomonitoring could be easily done in human samples(blood,hair,milk,and urine)with a multi-omics approach,which is a quick,reliable,and state-of-the-art technique.

Benzene and lead exposure assessment among occupational bus drivers in Bangkok traffic

Four environmental and biological monitoring sites were strategically established to evaluate benzene and lead exposure assessment at various traffic zones of Bangkok Metropolitan Region(BMR). Biological measurement of 48 non air-conditioned, male bus drivers was carried to study the relationship between individual exposure levels and exposure biomarkers. The study group was further sub-divided into four age groups(16—25, 26—35, 36—45 and 46—55 years old) to monitor the age—related exposure effects. A total of 12 unexposed persons were deliberately chosen as the control group. Measurement of unmetobolized benzene in blood and analysis of urinary tt-Muconic acid urine and urinary creatinine are recommended as biomarkers of benzene exposure. Measurement of lead in blood and urine is also recommended for the biological monitoring of lead exposure. During the monitoring period, benzene and lead levels at Yaowarat Road was C_6H_6: 42.46±3.88 μg/m 3, Pb: 0.29±0.03 μg/m 3 and decreased to C_6H_6: 33.5±1.35 μg/m 3, Pb: 0.13±0.01 μg/m 3 at Phahonyothin Road. Significant difference was established between the nonsmoking exposed group and nonsmoking control group for blood benzene concentrations ( P <0.001, two-tailed, Mann-Whiteney U test). Strong correlations were also found between trans-trans-Muconic acid concentrations in post shift samples and atmospheric benzene concentrations. Similarly, good correlation between all of biomarkers and lead level in air is established from automobile emissions.The analysis revealed that among the occupational population in the urban sites, the driver groups were found to have the highest risk of benzene and lead exposures derived from automobile emission.

Current Phthalate Exposure Risks of Rural Population in the Northwest China: Evidence from an Internal Exposure Study

Phthalates(PAEs)are synthetic chemicals widely used in industrial and personal consumer products as adhesives or plasticizers.PAEs have been demonstrated to have toxic effects on the human body.However,biological monitoring data for the internal PAE exposure levels of Chinese rural residents are still limited.The present study investigated the exposure levels of ten phthalate metabolites(mPAEs)of rural residents in Northwest China.The results showed that mPAEs were wildly prevalent in urine and the geometric mean concentration ofΣ10mPAEs was 957.02 ng mL^(–1)(adjusted by specific gravity).Mono-n-butyl phthalate(MBP)and metabolites of di(2-ethylhexyl)-phthalate(DEHP)were the most dominant mPAEs in urine,with specific gravity adjusted median concentrations of 174.67 and 156.30 ng mL^(–1),respectively.Urinary concentrations of mPAEs were significantly associated with age,body mass index and economic level(p<0.05).By calculating the percentage and relative conversion rate of DEHP metabolites,it was found that the degree of oxidative metabolism of DEHP in children was significantly higher than that in adults(p<0.05),indicating that the pathway and degree of DEHP oxidation were age-related.The risk assessment showed that 59.12%of rural residents may have a noncancer risk from PAE exposure.This study provides important basis for assessing the occurrence and exposure of urinary phthalate metabolites among rural residents in China.

Perfluoroalkane acids in human milk under the global monitoring plan of the Stockholm Convention on Persistent Organic Pollutants(2008-2019)

Within the global monitoring plan(GMP)established by article 16 of the Stockholm Convention on Persistent Organic Pollutants,perfluorooctane sulfonic acid(PFOS),perfluorooctanoic acid(PFOA),and perfluorohexane sulfonic acid(PFHxS)are recommended for analysis in core matrices to assess occurrence and changes geographically and with time.In 101 samples consisting of 86 national pools and 15 pools from States in Brazil obtained between 2008 and 2019,PFHxS was detected in 17%of the national pools and none in Brazil.PFOA and PFOS had a detection frequency of 100%and 92%,respectively.Other perfluoroalkane substances(PFAS)had either low detection frequencies and median values of zero(carboxylic acids C4-C11;except PFOA)or could not be quantified in any sample(sulfonic acids,C4-C10,and long-chain carboxylic acids,C_(12)-C_(14)).Correlation between PFOA and PFOS was moderately(r=0.58).Whereas median values were almost identical(18.9 pg/g f.w.for PFOS;18.6 pg/g f.w.for PFOA),PFOS showed larger ranges(<6.2 pg/g f.w.-212 pg/g f.w.)than PFOA(<6.2 pg/g f.w.-63.4 pg/g f.w.).It was shown that wealthier countries had higher PFOA concentrations than poorer countries.No difference in concentrations was found for samples collected in countries having or not having ratified the Stockholm Convention amendments to list PFOS or PFOA.The goal to achieve 50%decrease in concentrations within ten years was met by Antigua and Barbuda,Kenya,and Nigeria for PFOS and by Antigua and Barbuda for PFOA.In a few cases,increases were observed;one country for PFOS,four countries for PFOA.

Plasma concentrations of chlorinated persistent organic pollutants and their predictors in the general population of Algiers, Algeria

Background:Persistent organic pollutants(POPs)are subject of particular attention and in-depth studies which demonstrate their toxicity towards humans and biotope in general.POPs are therefore addressed by the Stockholm Convention globally with human milk or blood as matrix for effectiveness evaluation.Objectives:The objective of this study was to assess plasma concentrations of certain chlorinated POPs in subjects from the urban population in Algiers.Methods:A total number of 207 adult subjects were recruited in Algiers and plasma concentrations of Hexachlorobenzene(HCB),p,p’Dichlorodiphenyl DichloroEthylene(4,40 DDE)and Polychlorinated Biphenyls(PCBs)were determined by gas chromatography with mass spectrometry detection(GC-MS).Results:The nanogram per gram of lipids(ng g^(-1) lipids)geometric means of plasma concentrations of studied compounds were:6.09 for HCB,131.60 for 4,40 DDE,8.61 for PCB153,7.95 for PCB138 and 8.39 for PCB180.PCB 180,PCB 153 and PCB 138 showed a high correlation with each other(r>0.5).4,40 DDE concentrations were significantly higher in women and in subject with low educational level,whereas POPs were higher in older participants(>65 years old).Organochlorine pesticides(OCPs)and PCB153 concentrations were higher in overweight and obese subjects.There was no significant difference between POPs concentrations according to breastfeeding history,smoking status or fish consumption.Conclusions:Chlorinated POPs were detected in the blood plasma of adults living in Algiers.Plasma concentrations were consistent with those of several studies in the world.However,further investigations are needed to assess the exposure profile of subjects living near contaminated sites.