Low-cost particulate matter (PM) air quality sensors are becoming widely available and are being increasingly deployed in ambient and home/workplace environments due to their low cost, compactness, and ability to provide more highly resolved spatiotemporal PM concentrations. However, the PM data from these sensors are often of questionable quality, and the sensors need to be characterized individually for the environmental conditions under which they will be making measurements. In this study, we designed and assessed a cost-effective (∼$700) calibration chamber capable of continuously providing a uniform PM concentration simultaneously to multiple low-cost PM sensors and robust calibration relationships that are independent of sensor position. The chamber was designed and evaluated with a Computational Fluid Dynamics (CFD) model and a rigorous experimental protocol. We then used this new chamber to calibrate 242 Plantower PMS 3003 sensors from two production lots (Batches I and II) with two aerosol types: ammonium nitrate (for Batches I and II) and alumina oxide (for Batch I). Our CFD models and experiments demonstrated that the chamber is capable of providing uniform PM concentration to 8 PM sensors at once within 6% error and with excellent reliability (intraclass correlation coefficient > 0.771). The study identified two malfunctioning sensors and showed that the remaining sensors had high linear correlations with a DustTrak monitor that was calibrated for each aerosol type (R2 > 0.978). Finally, the results revealed statistically significant differences between the responses of Batches I and II sensors to the same aerosol (P-value<0.001) and the Batch I sensors to the two different aerosol types (P-value<0.001). This chamber design and evaluation protocol can provide a useful tool for those interested in systematic laboratory characterization of low-cost PM sensors.

Natural gas extraction (NGE) has expanded rapidly in the United States in recent years. Despite concerns, there is little information about the effects of NGE on air quality or personal exposures of people living or working nearby. Recent research suggests NGE emits polycyclic aromatic hydrocarbons (PAHs) into air. This study used low-density polyethylene passive samplers to measure concentrations of PAHs in air near active (n = 3) and proposed (n = 2) NGE sites. At each site, two concentric rings of air samplers were placed around the active or proposed well pad location. Silicone wristbands were used to assess personal PAH exposures of participants (n = 19) living or working near the sampling sites. All samples were analyzed for 62 PAHs using GC-MS/MS, and point sources were estimated using the fluoranthene/pyrene isomer ratio. ∑PAH was significantly higher in air at active NGE sites (Wilcoxon rank sum test, p < 0.01). PAHs in air were also more petrogenic (petroleum-derived) at active NGE sites. This suggests that PAH mixtures at active NGE sites may have been affected by direct emissions from petroleum sources at these sites. ∑PAH was also significantly higher in wristbands from participants who had active NGE wells on their properties than from participants who did not (Wilcoxon rank sum test, p < 0.005). There was a significant positive correlation between ∑PAH in participants' wristbands and ∑PAH in air measured closest to participants’ homes or workplaces (simple linear regression, p < 0.0001). These findings suggest that living or working near an active NGE well may increase personal PAH exposure. This work also supports the utility of the silicone wristband to assess personal PAH exposure.

Sleep disorders may pose a risk to workers in the workplace. We aimed to investigate the associations between metal fume fine particulate matter (PM2.5) and sleep quality in workers. We assessed the effects of personal exposure to metal fume PM2.5 on lung functions, urinary biomarkers, and sleep quality in shipyard welding workers. In total, 96 welding workers and 54 office workers were recruited in the present study; office workers were exposed to 82.1 ± 94.1 μg/m³ PM2.5 and welding workers were exposed to 2166.5 ± 3149.1 μg/m³. Welding workers had significantly lower levels of FEV25-75 than office workers (p < 0.05). An increase in 1 μg/m³ PM2.5 was associated with a decrease of 0.003 ng/mL in urinary serotonin (95% CI = −0.007–0.000, p < 0.05) in all workers and with a decrease of 0.001 ng/mL in serotonin (95% CI = −0.004–0.002, p < 0.05) in welding workers, but these were not observed in office workers. There was no significant association of PM2.5 with urinary cortisol observed in any workers. Urinary serotonin was associated with urinary Cu, Mn, Co, Ni, Cd, and Pb. Urinary cortisol was associated with Cu, Mn, Co, Ni, Cd, and Pb. Sixteen subjects were randomly selected from each of the office and welding workers for personal monitoring of sleep quality using a wearable device. We observed that welding workers had greater awake times than did office workers (p < 0.05). Our study observed that exposure to heavy metals in metal fume PM2.5 may disrupt sleep quality in welding workers.

Polybrominated diphenyl ethers (PBDEs) constitute an important group of brominated flame retardants that have been massively produced and extensively used in numerous everyday products, providing longer escape times in case of fire and thus saving lives, as well as reducing the damage of property. In recent years, PBDEs have been recognized as significant pollutants of the indoor environment. This article provides a synthesis and critical evaluation of the state of the knowledge about the occurrence of PBDEs in the indoor environment (air and dust in homes, workplaces and cars) in different countries in Europe, North America, Asia and Australia, as well as about the human exposure via indoor air inhalation and dust ingestion in comparison to outdoor air inhalation and dietary intake.

The environment of a large-scale vegetable production area can be exposed to antibiotic residues and antibiotic-resistant bacteria (ARB) via animal manure and irrigation with contaminated water, which can facilitate the dissemination of ARB. However, the occurrence of ARB in plantation areas and their dissemination in this environment remain largely unexplored. In total, 382 samples including those from vegetable (n = 106), soil (n = 87), well water (n = 24), river water (n = 20), river sediments (n = 20), farmer feces (n = 58) and farmer hands (n = 67) were collected in 2019 from a large-scale cultivation area in Shandong, China. Selective agar plates were used to screen for carbapenem-resistant Enterobacteriaceae (CRE) and whole-genome sequencing and Southern blotting were used to characterise isolates and mobile genetic elements carrying carbapenem resistance determinants. A total of nine NDM-5-producing isolates of Escherichia coli, Klebsiella pneumoniae, and Citrobacter spp. were identified from environmental sources and human feces, all of which were multidrug-resistant. Single nucleotide polymorphism analysis suggested clonal transmission of carbapenem-resistant Citrobacter sedlakii within greenhouse soils in the area. Eight of the isolates carried closely related or identical IncX3 plasmids carrying blaNDM₋₅, which were shown to be conjugative via filter mating experiments, indicating the highly transmissible nature of this genetic element. Isolates of E. coli and Citrobacter freundii were detected in the feces of local farm workers and contained similar IncX3 plasmids with blaNDM₋₅ environmental isolates, suggesting a potential risk of CRE transfer from the work environment to the farm workers. Thus, further research is required to investigate the potential health risks associated with environmental exposure to CRE in vegetable cultivation areas.

Contamination status, potential emission sources, environmental fate, and human exposure risk of polybrominated diphenyl ethers (PBDEs) are reviewed for indoor and outdoor dust from Southeast Asian countries, under an international comparison point of view. PBDEs have been widely detected in house, workplace, car, and road dust samples collected from Indonesia, Philippines, Singapore, Thailand, and Vietnam. The highest PBDE levels up to hundreds of μg/g were found in settled dust from some e-waste processing areas in Thailand and Vietnam. Concentrations of PBDEs in house, car, and road dust from this region were generally lower than those reported in China and Western developed countries. BDE-209 was the most predominant congener in almost all analyzed samples, reflecting the widespread application of materials and products treated with commercial deca-BDE mixtures in this region. The market demand and application rate of commercial PBDE mixtures in Southeast Asia were lower than those documented for other regions in the world. As a result, PBDE contamination levels in the environments (e.g., indoor and outdoor dust) and associated risks in these countries were not significantly high. However, more attention should be paid to informal processing activities and management strategies for modern wastes such as e-waste, plastics, and end-of-life vehicles. There exist several knowledge gaps about spatiotemporal trends, potential sources, risk assessment, inventory, management, and legislation regarding PBDEs in dust from this region, which should be filled by additional comprehensive, detailed studies with relevant inter-country/regional monitoring schemes.

Child labor is a major challenge in the developing countries and comprehensive health hazard identification studies on this issue are still lacking. Therefore, the current study is an effort to highlight the health concerns of child labor exposed in the key small scale industries of Sialkot, Pakistan. Our findings revealed jolting levels of heavy metals in the urine, blood, serum, saliva, and hair samples collected from the exposed children. For example, in the urine samples, Cd, Cr, Ni, and Pb were measured at the respective concentrations of 39.17, 62.02, 11.94 and 10.53 μg/L in the surgical industries, and 2.10, 4.41, 1.04 and 5.35 μg/L in the leather industries. In addition, source apportionment revealed polishing, cutting, and welding sections in the surgical industries and surface coating, crusting, and stitching sections in the leather industries were the highest contributors of heavy metals in the bio-matrices of the exposed children, implying the dusty, unhygienic, and unhealthy indoor working conditions. Further, among all the bio-matrices, the hair samples expressed the highest bioaccumulation factor for heavy metals. In accordance with the heavy metal levels reported in the exposed children, higher oxidative stress was found in the children working in the surgical industries than those from the leather industries. Moreover, among heavy metals’ exposure pathways, inhalation of industrial dust was identified as the primary route of exposure followed by the ingestion and dermal contact. Consequently, chemical daily intake (CDI), carcinogenic and non-carcinogenic hazard quotients (HQs) of heavy metals were also reported higher in the exposed children and were also alarmingly higher than the corresponding US EPA threshold limits. Taken all together, children were facing serious health implications in these industries and need immediate protective measures to remediate the current situation.

Polybrominated Diphenyl Ethers (PBDEs) are ubiquitous in the indoor environment owing to their use in consumer products and various studies around the world have found higher concentrations indoors than outdoors. Central air conditioner (A/C) systems have been widely used in many workplaces, therefore, studying of PBDEs in central A/C filter dust is useful to better understand the occurrences and health implications of PBDEs in indoor environments. The present study examined the occurrence of PBDEs in central A/C filter dust collected from various workplaces (n = 20) in Thessaloniki, Greece. The sum concentrations of 21 target congeners (∑21PBDE) in A/C dust ranged between 84 and 4062 ng g−1 with a median value of 1092 ng g−1, while BDE-209 was found to be the most abundant BDE congener. The daily intake via dust ingestion of PBDEs estimated for the employees of the occupational settings ranged from 3 to 45 ng day−1 (median 12 ng day−1).

International audience | In a globalized world, the world trade fleet plays a pivotal role in limiting transport costs. But, the management of obsolete ships is an acute problem, with most Ship Recycling Facilities (SRF) situated in developing countries. They are renowned for their controversial work and safety conditions and their environmental impact. Paradoxically, dismantlement is paid for by the shipowners in accordance with international conventions therefore it is more profitable for them to sell off ships destined for scrapping. Scuttling, the alternative to scrapping, is assessed in the present review to compare the cost/benefit ratios of the two approaches. Although scrapping provides employment and raw materials – but with environmental, health and safety costs – scuttling provides fisheries and diving tourism opportunities but needs appropriate management to avoid organic and metal pollution, introduction of invasive species and exacerbation of coastal erosion. It is also limited by appropriate bottom depth, ship type and number. The present review inventories the environmental, health, safety, economic, and forensic aspects of each alternative.

Feedback on personal exposure to air pollution, noise or extreme temperatures through wearable sensors or sensors installed at home or in the workplace can offer information that might motivate behaviours to mitigate exposure. As personal measurement devices are becoming increasingly accessible, it is important to evaluate the effects of such sensors on human perception and behaviour. We conducted a systematic literature research and identified 33 studies, analysing the effects of personal feedback on air pollution, noise and temperatures. Feedback was given through reports including different forms of visualization, in-person or over the telephone, or directly on the sensor or through a phone app. The exposure feedback led to behaviour changes particularly for noise and temperature feedback while findings on behaviour adaptation to avoid air pollution were mixed. Most studies reported increased awareness and knowledge from receiving exposure feedback. Many participants in studies on air pollution reported low levels of self-efficacy regarding exposure mitigation. For a better understanding of the effects of personal exposure feedback, more studies are required, particularly providing feedback from wearable sensors measuring outdoor air pollution, noise and temperature.