Recycling Workers Research Articles

Urinary metals and their associations with DNA oxidative damage among e-waste recycling workers in Hong Kong

Recycling electronic waste (e-waste) poses risks of metal exposure, potentially leading to health impairments. However, no previous study has focused on this issue in Hong Kong. Therefore, from June 2021 to September 2022, this study collected urine samples from 101 e-waste workers and 100 office workers in Hong Kong to compare their urinary levels of metals using ICP-MS. Among the 15 included metals (with detection rates above the 70 % threshold), eight showed significantly higher urinary concentrations (unit: μg/g creatinine) in e-waste workers compared to office workers: Li (25.09 vs. 33.36), Mn (1.78 vs. 4.15), Ni (2.10 vs. 2.77), Cu (5.81 vs. 9.23), Zn (404.35 vs. 431.52), Sr (151.33 vs. 186.26), Tl (0.35 vs. 0.43), and Pb (0.69 vs. 1.16). E-waste workers in Hong Kong generally exhibited lower metal levels than those in developing regions but higher than their counterparts in developed areas. The urine level of 8-hydroxy-2-deoxyguanosine (8-OHdG) was determined by HPLC-MS/MS, and no significant difference was found between the two groups. Multiple linear regression models revealed no significant association between individual metal and urinary 8-OHdG concentrations. However, the metal mixture was identified to marginally elevate the 8-OHdG concentrations (1.12, 95 %CI: 0.04, 2.19) by quantile g‑computation models, with Mn and Cd playing significant roles in such effect. In conclusion, while the metal levels among Hong Kong e-waste workers compared favorably with their counterparts in other regions, their levels were higher than those of local office workers. This underscores the need for policymakers to prioritize attention to this unique industry.

Creating a sustainable closed-loop supply chain: An incentive-based contract with third-party E-waste collector

This paper proposes a closed-loop supply chain model to study the impact of product returns and awareness program on e-waste supply chain. The study focuses on the sustainability aspects of e-waste management and the effects such initiatives bring about to the environment at large. Reusing and recycling of collected products in manufacturing will improve the supply of scarce resources and reduce reliance on virgin raw materials. Engaging in CLSC can enhance brand reputation and competitiveness through sustainability while reducing the health risks to informal recycling workers by formalizing practices. The proposed model consists of a manufacturer, retailer, and third-party collector (TPC) under wholesale price and incentive contracts with deterministic demand. From the analysis it is observed that integrating a third-party collector with higher recycling rate boosts the total profit of the decentralized setting with a TPC. The centralized model, with a single decision maker, results in lower retail prices and higher collection rates compared to the decentralized models thereby commanding a higher overall profit.

HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe.The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum.Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 μg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population.This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

Awareness, Safety Practices and Associated Factors Among E-Waste Recycling Workers in Bangladesh.

Awareness of electronic waste (e-waste) improves safety practices among workers, thereby reducing health risks associated with pollutants. Investigating the awareness and safe practices among these workers could help identify areas for improvement, a task not yet undertaken in Bangladesh. Consequently, this study aimed to examine the awareness, safety measures, and associated factors among e-waste workers in the country. In this cross-sectional study, 236 workers from an e-waste recycling facility located near Dhaka were interviewed using a semi-structured questionnaire from August to September 2022. Eight questions captured information on socio-demographics and work factors, 24 questions on e-waste awareness, and 11 questions on safety practices. Total awareness and safety scores were calculated and categorized as "good" and "poor" based on a cut-off point of 80% of the total score. Bivariate and regression analyses were done to determine associated factors. Only 25% of workers had good e-waste awareness; major knowledge gaps were regarding minimization, health hazards, and environmental impact. Good awareness was significantly associated with female gender, higher education, income, smoking, experience ⩾5 years, and training. About 58% followed good safety practices, but the use of boots and helmets was inadequate. Good safety practices were significantly associated with higher education, income, smoking, experience, training, and overtime work. On multivariable analysis, those with higher education had 12 times (95% CI 4.83-32.81) and 6 times (95% CI 2.94-12.81) higher odds of good awareness and practices, respectively. Trained workers had 3.6 times (95% CI 1.67-7.52) higher odds of good practices. There was a significant correlation between awareness and practices (r = .70, P < .001). The study found poor awareness and inadequate safety practices related to e-waste among the workers. Urgent interventions like training, the use of protective gear, and stringent policies are warranted to increase awareness and safety behaviors.

Assessing Neurobehavioral Alterations Among E-waste Recycling Workers in Hong Kong

BackgroundE-waste workers in Hong Kong are handling an unprecedented amount of e-waste, which contains various neurotoxic chemicals. However, no study has been conducted to evaluate the neurological health status of e-waste workers in Hong Kong. This study aimed to evaluate the prevalence of neurobehavioral alterations and to identify the vulnerable groups among Hong Kong e-waste workers. MethodsWe recruited 109 Hong Kong e-waste workers from June 2021 to September 2022. Participants completed standard questionnaires and wore a GENEActiv accelerometer for seven days. Pittsburgh Sleep Quality Index and Questionnaire 16/18 (Q16/18) were used to assess subjective neurobehavioral alterations. The GENEActiv data generated objective sleep and circadian rhythm variables. Workers were grouped based on job designation and entity type according to the presumed hazardous level. Unconditional logistic regression models measured the associations of occupational characteristics with neurobehavioral alterations after adjusting for confounders. ResultsWhile dismantlers/repairers and the workers in entities not funded by the government were more likely to suffer from neurotoxic symptoms in Q18 (adjusted odds ratio: 3.18 [1.18–9.39] and 2.77 [1.10–7.46], respectively), the workers from self-sustained recycling facilities also have poor performances in circadian rhythm. Results also showed that the dismantlers/repairers working in entities not funded by the government had the highest risk of neurotoxic symptoms compared to the lowest-risk group (i.e., workers in government-funded companies with other job designations). ConclusionThis timely and valuable study emphasizes the importance of improving the working conditions for high-risk e-waste workers, especially the dismantlers or repairers working in facilities not funded by the government.

Radiation safety assessments for radioactive concrete recycling workers and residents

Carried out was the assessment of the radiation safety for the recycling workers of the radioactive concrete generated from nuclear power plants and nearby residents. Decommissioning of a nuclear power plant with an electric output of 1000 MW generates approximately 500,000 tons of concrete waste. It is important to reduce the volume of concrete waste to reduce the costs of decommissioning projects. For this purpose, the low-level radioactive cement powder from bioshield concrete is recycled as a solidifying agent. The number of radioactive concrete waste drums to be disposed is reduced by extracting cement from the radioactive concrete and using it as a solidifying agent, rather than using cement from general industrial waste. Various exposure scenarios exist, and it is necessary to evaluate the radiation dose in each scenario. In this study, seven scenarios were selected and evaluated. The radioactive exposure to facility workers, nuclear power plant workers, and landfill management workers is within the annual dose limit, even if they work 2000 h per year. A loader can work close to the drum for 90–93 h per year, and a truck driver can drive 621 one-way trucks per year. Dose evaluations for road users and residents after landfill closure showed that both had values far below the dose limit for the public. Bioshield concrete recycling was confirmed to be radiologically safe in all scenarios if certain conditions were satisfied. Thus, this study showed that cement powder from bioshield concrete could be used safely without exceeding the radiation safety limits for workers and the public when recycling concrete.

Organophosphate ester (OPE) exposure among waste recycling and administrative workers in Denmark using silicone wristbands

In a recent estimate, 96 million tons of hazardous waste were produced in the European Union, most of which were handled among the member states. Organophosphate esters (OPEs) are applied as flame retardants and plasticizers and are present in many products, e.g., electronics, which end up in the hazardous waste stream upon disposal. Given the growing body of information suggesting potential adverse health effects of OPEs, waste recycling workers who handle hazardous waste could potentially be at risk of elevated exposure to these chemicals. Using silicone wristbands, we evaluated OPE exposure among waste recycling workers who handled hazardous waste and compared their exposure to that of administrative workers from the same waste companies. Wristbands were extracted and analyzed for six OPEs, which were all detected in >75% of wristbands. Overall, the sum of tris(2-chloroisopropyl) phosphate (∑TCIPP) isomers was the most abundant OPE across all wristbands collected within the study. In general, the sum of tri(methyl phenyl) phosphate isomers (∑TMPP) was elevated for all waste workers (10β = 7.9), whereas tri-n-butyl phosphate (TnBP), tris(1,3-dichloroisopropyl) phosphate (TDCIPP), and ∑TMPP were 3–12 times higher among those specifically handling electronic and hazardous waste compared to the administrative workers (p < 0.05). Repeated wristband measurements from the same worker had fair to good consistency in OPE concentrations (intraclass correlation coefficients = 0.54–0.77), except for the two most volatile chlorinated OPEs. Taken together, our results suggest that waste recycling workers who handle electronic and hazardous waste have significantly elevated exposure to OPEs, and efforts to reduce these exposures should be considered.

Are UK E-waste recycling facilities a source of environmental contamination and occupational exposure to brominated flame retardants?

Investigations into the impacts of regulated electrical and electronic waste (e-waste) recycling activities on urban environments in Europe remain rather scarce. In this study, dust samples taken both inside and outside of five UK e-waste recycling facilities were analysed for concentrations of polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and hexabromocyclododecane (HBCDD). Average concentrations of ∑BFRs in dust inside and outside UK e-waste recycling facilities were 12,000 ng/g and 180 ng/g, with median concentrations of 7500 ng/g and 85 ng/g, respectively. BDE-209 and decabromodiphenyl ethane (DBDPE) were the most abundant BFRs in both indoor and kerb dust, making a combined contribution to ∑BFRs of ~90 % on average. While four out of the five studied e-waste facilities showed a lack of significant impact on BFR contamination in surrounding environment, one of the studied e-waste recycling facilities was identified as a likely source of BFR contamination to UK urban environments, with industrial activities as another potential source of NBFRs. Occupational exposure of UK e-waste recycling workers to BFRs via dust ingestion was generally lower than that estimated for e-waste recyclers from other countries, but was comparable to BFR exposure via dust ingestion of UK office workers. Our estimates suggested that health burdens posed by dust ingestion of BFRs were minimal for UK e-waste recycling workers.

Driving Green Job Opportunities in Sustainable Waste Management through Co-Production Strategies: Informal Recycling Workers, Municipalities, and the National Agenda—A Case Study of İzmir

Informal recycling workers (IRWs), including waste pickers (WPs) and waste sorters, are essential constituents of sustainable ecosystems in many cities in the Global South. Despite their valuable contributions to the economic and environmental dimensions of sustainable urban waste recycling, most IRWs work in precarious conditions. This paper examines recent efforts by local municipalities in Izmir to implement co-production design as a new institutional arrangement to generate green jobs for informal workers that provide high and stable incomes, job security, and social recognition. Using qualitative analyses of recent developments in the legal framework and in-depth interviews with key stakeholders, this paper identifies the following challenges associated with the current co-production efforts as its main findings: the lack of fiscal and legislative support from the central government; failure to include all IRWs in the co-production schemes; and the potential exclusion of marginalized communities due to the arbitrary requirements of a security clearance, which limit the inclusion of IRWs in co-production efforts.

SELF-REPRESENTATION OF WASTE PICKERS ON SOCIAL MEDIA: SEMIOTIC ANALYSIS OF TWEETS OF @atikkagit DURING THE COVID-19 PANDEMIC

Waste pickers have been excluded from society because of their appearance due to working conditions and poverty, as well as being deprived of fundamental human rights such as the right to health and the right to education. Moreover, the advocacy of the waste pickers is presented as a spectacle in the mainstream media content (whether online or in the mass media) that protects the interests of the dominant ideology. Therefore, waste pickers, who are neither visible on the street nor in other public spaces, try to construct a self-representation through social media. The institutional form of this self-representation is the Recycling Workers Association, which was established in 2013, and the social media accounts of this association. Waste pickers looking for recyclable materials in dumpsters or working in waste yards faced a vital threat by not being able to earn their daily income due to both the risk of disease caused by COVID-19 and the curfews/restrictions in 2020. This study aims to discuss the self-representation of waste pickers, who strove at moulding public opinion during the curfews, on social media. This study is important in terms of understanding the efforts of others to gain visibility in society by using social media. The study is limited to the content shared on the @atikkagit Twitter account during the curfew, and the semiotic analysis method is used in the study. According to the research findings, the self-representation of waste pickers in an emergency due to the COVID-19 epidemic is seen within the framework of poverty and social aid rather than a struggle for rights.

Exposure characteristics and neurological health concerns among e-waste recycling workers in Hong Kong: preliminary findings

Exposure characteristics and neurological health concerns among e-waste recycling workers in Hong Kong: preliminary findings

Work Task Association with Lead Urine and Blood Concentrations in Informal Electronic Waste Recyclers in Thailand and Chile.

The informal recycling of electronic waste (“e-waste”) is a lucrative business for workers in low- and middle-income countries across the globe. Workers dismantle e-waste to recover valuable materials that can be sold for income. However, workers expose themselves and the surrounding environment to hazardous agents during the process, including toxic metals like lead (Pb). To assess which tools, tasks, and job characteristics result in higher concentrations of urine and blood lead levels among workers, ten random samples of 2 min video clips were analyzed per participant from video recordings of workers at e-waste recycling sites in Thailand and Chile to enumerate potential predictors of lead burden. Blood and urine samples were collected from participants to measure lead concentration. Boosted regression trees (BRTs) were run to determine the relative importance of video-derived work variables and demographics, and their relationship with the urine and blood concentrations. Of 45 variables considered, five job characteristics consisting of close-toed shoes (relative importance of 43.9%), the use of blunt striking instruments (14%), bending the back (5.7%), dismantling random parts (4.4%), and bending the neck (3.5%) were observed to be the most important predictors of urinary Pb levels. A further five job characteristics, including lifting objects <20 lbs. (6.2%), the use of screwdrivers (4.2%), the use of pliers/scissors (4.2%), repetitive arm motion (3.3%), and lifting objects >20 pounds (3.2%) were observed to be among the most important factors of blood Pb levels. Overall, our findings indicate ten job characteristics that may strongly influence Pb levels in e-waste recycling workers’ urine and blood.

Mercury Exposure among E-Waste Recycling Workers in Colombia: Perceptions of Safety, Risk, and Access to Health Information.

Exposures to the toxic element mercury (Hg) are exceptionally high among recycling workers globally. Recycling is a growing sector in Colombia, yet workers who directly handle e-waste are often unaware of the risks of exposure to mercury from post-consumer lighting products (e.g., fluorescent lamps). This qualitative study aimed to understand how recycling workers perceive their own risks from mercury exposure and how they find information about these risks, through interviews (n = 35) at the three largest formal recycling facilities in Colombia. Workers’ risk perception was generally disconnected from their likely actual exposure to mercury, instead often seen juxtaposed to co-workers who worked more directly with hazardous waste. Recycling workers, who were predominantly men from lower-income socioeconomic backgrounds, had limited knowledge of health risks due to mercury exposure and were more likely to receive health-related information from informal sources. Over a third of interviewees had searched online for information about occupational health risks of mercury, but these searches were perceived as unsatisfactory due to information being difficult to find, not available in Spanish, or related to mercury exposure via seafood or mining rather than recycling. Workers expressed (over)confidence in personal protective equipment and concern about frequent employee turnover. This study points to weaknesses in environmental health literacy and public health communication around toxic exposures to mercury in the workplace. Stronger regulation and enforcement are needed to prevent toxic exposures and promote worker health equity.

Metal Levels, Genetic Instability, and Renal Markers in Electronic Waste Workers in Thailand.

Background: Informal electronic waste (e-waste) recycling is an increasingly important industry worldwide. However, few studies have studied the health risks in this group of workers. Objective: To assess the associations between occupational exposures to metals and genetic instability and renal markers among e-waste recycling workers. Methods: We recruited informal e-waste recycling workers from a community in northeastern Thailand. Participants completed a questionnaire, several health measurements, and provided urine and blood samples, which we then analyzed for a number of metals including lead (Pb), cadmium (Cd), and manganese (Mn). Samples were analyzed for a marker of RNA and DNA damage (ie, oxidative stress), 8-hydroxy-2'-deoxyguanosine (8-OHdG). Glomerular filtration rate (GFR) and fractional excretion of calcium (FECa%) were measured as markers of renal function. Correlations and regression models were used to assess associations between these various factors. Results: We found significantly higher levels of Cd and Pb in blood of men compared with those in women. Men who worked >48 hours/week had significantly higher levels of 8-OHdG compared with men who worked ≤48 hours/week. Smoking was significantly associated with higher blood Pb and Cd concentrations among men. Conclusion: Our results suggest gender differences in both blood concentrations of metals associated with e-waste recycling and smoking and highlight potentially elevated oxidative stress associated with longer work hours. Health promotion efforts are needed among informal e-waste recyclers to reduce possible risks of renal damage and cancer.

Workers' perception of hazards on recycling sorting facilities in São Paulo, Brazil.

The paper discusses views, perceptions, experiences, knowledge and behaviors related to occupational risks among recycling workers. Data collection involved field observation and two focus groups in each site. Narratives were recorded, transcribed, and analyzed for themes. Findings are presented according to the following topics: economic and environmental value of recycling; aspects of employment in the cooperative system; occupational hazards; and suggestions of improvements. Municipal programs of selective collection, as implemented in most Brazilian municipalities, still need improvements to achieve their goals and objectives. We learned that organizing recycling workers in cooperatives, despite its broad acceptance as a replacement to informal garbage collection in streets and landfills, only brought small progress regarding the safety and quality of life of cooperative workers. Recycling workers noticed the existence of workplace hazards, but seemed resigned to the situation, considered them as part of the job and did not communicate their needs to supervisors. They ignored the existence of some measures to prevent hazards and sometimes even created work practices and alternatives that endangered their own health.

Urinary Metabolites of Organophosphate Esters (OPEs) in Electronic Waste Recycling Workers from the Province of Quebec, Canada

Background: Organophosphate esters (OPEs), which are used as flame retardants and plasticizers, have been measured in the air of electronic waste recycling (E-recycling) plants. Numerous studies suggest that exposure to OPEs may result in adverse health effects and constitute a potential health risk for E-recycling workers. However, data on urinary OPE metabolites in occupationally exposed workers is scarce.Objective: To measure urinary OPE metabolites in E-recycling workers and assess their relationship with personal air OPE levels.Methods: Levels of 13 OPE metabolites were measured, at the end of the work shift, in urine samples from 56 workers (four facilities in Quebec, Canada). Air levels of 11 OPEs were measured in 8-hour personal samples with OSHA XAD-2 versatile samplers. The relationship between air OPE levels and urinary metabolite levels was determined using Spearman&amp;#8217;s rank correlation.Results: Nine of the 13 urinary OPE metabolites were detected in more than 50% of samples. The OPE metabolites with the highest median levels were 1-hydroxy-2-propyl bis (1-chloro-2-propyl) phosphate (OH-BIPCPP) (median: 2.2 ng/mL; maximum: 26), diphenyl phosphate (DPhP) (median: 2.1 ng/mL; maximum: 19), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) (median: 1.2 ng/mL; maximum: 7.4), and bis(2-chloroethyl) carboxymethyl phosphate (tris(1,3-dichloro-2-propyl) phosphate (BICECMP) (median: 0.5 ng/mL; maximum: 16). Urinary OPE metabolite levels were not significantly correlated with air OPE levels (p values were above 0.05).Discussion: The median urinary levels of BDCIPP and DPhP were higher than those observed in workers from a Chinese E-recycling site, although the timing of sample collection differed. These findings suggest that workers from E-recycling plants are exposed to OPEs, but that exposure through routes other than inhalation, and possibly non-occupational sources, may be more important contributors to the absorbed dose.

Role of Occupational Therapy in Preventing Work-Related Musculoskeletal Disorders With Recycling Workers: A Pilot Study.

Little is known about injury prevention in recycling workers; therefore, in this study, I aimed to identify physical and psychosocial risk factors for employees involved in single-stream recycling and to explore strategies for prevention and wellness. Fifteen participants who were either recycling workers or supervisors located throughout seven locations on an urban university campus participated. A mixed-methods research design was used to obtain data through a variety of standardized work environment and health questionnaires and semistructured interviews. Approximately 80% of participants expressed satisfaction with their jobs; 50% reported having a musculoskeletal injury; and 33% reported a lack of support from coworkers or supervisors, which created stress and anxiety. Additional risk factors included poor body mechanics, equipment issues, poor social interactions, and lack of supervisor knowledge for prevention. Occupational therapy practitioners are well situated to support preventive interventions that address the combined physical and psychosocial needs of recycling workers.

Polychlorinated Biphenyls (PCBs) in Human Hair and Serum from E-Waste Recycling Workers in Southern China: Concentrations, Chiral Signatures, Correlations, and Source Identification.

Hair is increasingly used as a biomarker for human exposure to persistent organic pollutants (POPs). However, the internal and external sources of hair POPs remain a controversial issue. This study analyzed polychlorinated biphenyls (PCBs) in human hair and serum from electronic waste recycling workers. The median concentrations were 894 ng/g and 2868 ng/g lipid in hair and serum, respectively. The PCB concentrations in male and female serum were similar, while concentrations in male hair were significantly lower than in female hair. Significant correlations between the hair and serum PCB levels and congener profiles suggest that air is the predominant PCB source in hair and that hair and blood PCB levels are largely dependent on recent accumulation. The PCB95, 132, and 183 chiral signatures in serum were significantly nonracemic, with mean enantiomer fractions (EFs) of 0.440-0.693. Nevertheless, the hair EFs were essentially racemic (mean EFs = 0.495-0.503). Source apportionment using the Chemical Mass Balance model also indicated primary external PCB sources in human hair from the study area. Air, blood, and indoor dust are responsible for, on average, 64.2%, 27.2%, and 8.79% of the hair PCBs, respectively. This study evidenced that hair is a reliable matrix for monitoring human POP exposure.

Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers.

Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people’s livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen’s Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman’s ρ 0.46, p < 0.001). A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.

Polybrominated Diphenyl Ethers (PBDEs) in Paired Human Hair and Serum from e-Waste Recycling Workers: Source Apportionment of Hair PBDEs and Relationship between Hair and Serum

Human hair has been widely used as a bioindicator for human persistent organic pollutants (POPs) exposure, but studies on the sources of hair POPs and the relationship between hair and body burden are limited. This study analyzed the possible source apportionment of hair PBDEs and examined the relationship between PBDE concentrations in paired hair and serum from e-waste recycling workers. Using the ratio of BDE 99/47 and BDE 209/207 as indices, we calculated that only 15% of the highly brominated congeners (nona- and deca-BDE congeners) comes from exogenous (external) exposure for both female and male hair, but an average of 64% and 55% of the lower-brominated congeners (tetra- to penta-BDE congeners) come from exogenous exposure for female and male hair, respectively. The higher contribution of exogenous exposure for less-brominated congeners could be related to their relatively lower log KOW and higher volatility than higher-brominated congeners, which make them more readily to evaporate from dust and then to be adsorbed on hair. Higher hair PBDE levels and higher exogenous exposure of less-brominated congeners in females than in males can be attributed to a longer exogenous exposure time for females than males. Significant positive relationships were found in tri- to hepta-BDE congeners (BDE 28, 47, 66, 85, 100, 153, 154, and 183) (R = 0.36-0.55, p < 0.05) between hair and serum, but this relationship was not found for octa- to deca-BDE. Difference in the half-lives between highly brominated congeners and less-brominated congeners could be a reason. This result also implied that we should treat the results of correlation analyses between hair and other organs cautiously.