Passive Air Samplers Research Articles

Occurrence and air-soil exchange of organophosphate flame retardants in the air and soil of Dalian, China

We investigated the concentrations, distributions, potential sources, and air-soil exchange of 10 OPFRs in the air and soil of Dalian. The concentrations of Σ10OPFRs in the soil were in the range of 1.07–288 ng/g (mean: 14.0 ng/g), while the concentrations of Σ10OPFRs in the passive air samples were in the range of 313–4760 pg/m3 (mean: 1630 pg/m3). Generally, the concentrations of OPFRs are relatively high in urban areas compared with those in suburban and rural areas, indicating the influence of intensive anthropogenic activities on local OPFR concentrations. Tris(2-chloroisopropyl) phosphate (TCIPP) was the most abundant congener, followed by tris(2-chloroethyl) phosphate (TCEP) and tri-n-butyl phosphate (TNBP). Spearman correlation analysis illustrated that OPFRs in the air shared common sources, while the sources of OPFRs in the soil were diverse. Net volatilization of TNBP from the soil to the air was observed at all sampling sites, whereas opposite trends were observed for TCIPP, TDCIPP, TBOEP, TPHP, EHDPP, TEHP, TPPO, and TMPP. The exchange trends of TCEP were characterized as volatilization in urban areas, but equilibrium in rural ones. TCEP showed the highest volatilization flux (1100 ng/m3/d), whereas TCIPP showed the highest deposition flux (−171 ng/m3/d). The significant diffusive fluxes of certain OPFRs, especially of those with suspected toxicities, suggested potential high exposure levels to these chemicals.

Cyclic volatile methylsiloxanes (cVMSs) in the air of the wastewater treatment plants in Dalian, China - Levels, emissions, and trends

Passive air samplers comprising sorbent-Tenax-TA thermal desorption tubes were applied for monitoring cyclic volatile methyl siloxanes (cVMSs) in the air above the aeration tanks of eight wastewater treatment plants (WWTPs, including five “open” and three “close” plants) in Dalian, China. The aim was to investigate the inputs of cVMSs from WWTPs to the air throughout a year (June 2016–July 2017). The ∑cVMS concentrations were averaged at 3.14 ± 6.84 μg·m−³ with D5 as the dominant compound (contributing to 63.8% of the ∑cVMS concentration). The annual average concentrations of D4, D5, and D6 in the air of the “close” WWTPs were 5.33 ± 4.63, 13.4 ± 14.4, and 1.05 ± 1.47 μg·m−³, and 1.31 ± 1.29, 1.57 ± 2.01, and 0.301 ± 0.340 μg·m−³ in the air from the “open” WWTPs, respectively. For both the close and open aeration tanks, the concentration of ∑cVMSs was the highest in summer and the lowest in winter, showing a significant correlation with ambient temperature (linear regression; p < 0.01). A simplified Gaussian dispersion model and a single chamber model were introduced to estimate annual emissions (kg·yr−1) of cVMSs from “open” and “close” WWTPs, ranging from 86.9 to 165 kg yr−1 and from 203 to 278 kg yr−1, respectively. Examining the relationship between the per capita emissions of cVMSs and average property prices, our results indicated that a greater amount of personal care products were used/discharged by people with relatively higher socioeconomic status.

Development of polyoxymethylene passive sampler for assessing air concentrations of PCBs at a confined disposal facility (CDF)

In this study, 76 μm polyoxymethylene (POM) strips were evaluated as a passive air sampler (PAS) for monitoring the volatile emissions from dredged material placed in confined disposal facilities (CDF). Laboratory evaluations were used to assess the uptake kinetics, average equilibrium time, and estimate the POM-air partition coefficients (KPOM-A) of 16 PCB congeners. The uptake kinetics defined the effective averaging time for air sampling and ranged from about a week for dichlorobiphenyls to 2 weeks or more for tetra- and pentachlorobiphenyls at ∼20 °C under internal mass transfer resistance control which was applicable for Log KPOM-A < 8. The measured Log KPOM-A for PCBs ranged from 5.65 to 9.34 and exhibited an average deviation of 0.19 log unit from the theoretical value of KPOM-W/KAW. The PAS approach was then tested with a preliminary field application (n = 17) at a CDF allowing equilibration over 42 days. The field application focused on lower congener PCBs as a result of the estimated increase in KPOM-A and longer uptake times expected at the low ambient temperatures during the field study (average of 3.5 °C). Total PCB air concentrations around the CDF averaged 0.32 ng/m3 and varied according to proximity to placement of the dredged materials and predominant wind directions. Average PAS concentration of low congener number PCBs (15, 18, 20/28, 31) were compared to available high volume air sampler (HVAS) measurements. The PAS concentrations were within 20% of HVAS in the dominant north and south directions and showed similar trends as east and west HVAS samplers although PAS concentrations were as much as an order of magnitude below the west HVAS.

Environmental surveillance and adverse neonatal health outcomes in foals born near unconventional natural gas development activity

Studies of neonatal health risks of unconventional natural gas development (UNGD) have not included comprehensive assessments of environmental chemical exposures. We investigated a clustering of dysphagic cases in neonatal foals born between 2014 and 2016 in an area of active UNGD in Pennsylvania (PA),USA. We evaluated equine biological data and environmental exposures on the affected PA farm and an unaffected New York (NY) farm owned by the same proprietor. Dams either spent their entire gestation on one farm or moved to the other farm in late gestation. Over the 21-month study period, physical examinations and blood/tissue samples were obtained from mares and foals on each farm. Grab samples of water, pasture soil and feed were collected; continuous passive sampling of air and water for polycyclic aromatic hydrocarbons was performed. Dysphagia was evaluated as a binary variable; logistic regression was used to identify risk factors. Sixty-five foals were born, 17 (all from PA farm) were dysphagic. Odds of dysphagia increased with the dam residing on the PA farm for each additional month of gestation (OR = 1.4, 95% CI 1.2, 1.7, p = 6.0E-04). Males were more likely to be born dysphagic (OR = 5.5, 95% CI 1.2, 24.5, p = 0.03) than females. Prior to installation of a water filtration/treatment system, PA water concentrations of 3,6-dimethylphenanthrene (p = 6.0E-03), fluoranthene (p = 0.03), pyrene (p = 0.02) and triphenylene (p = 0.01) exceeded those in NY water. Compared to NY farm water, no concentrations of PAHs were higher in PA following installation of the water filtration/treatment system. We provide evidence of an uncommon adverse health outcome (dysphagia) in foals born near UNGD that was eliminated in subsequent years (2017–2019) following environmental management changes. Notably, this study demonstrates that domestic large animals such as horses can serve as important sentinels for human health risks associated with UNGD activities.

PUF PAS를 이용한 대기 중 PCBs 농도 산정

This study was conducted to evaluate the use of low volume air sampler (LVAS) and polyurethane foam disk passive air samplers (PUF PAS) for better measurement of atmospheric polychlorinared biphenyls (PCBs) concentrations. Air samples were collected by a low volume air sampler (LVAS) and PUF PAS, a total of two pairs were continuously collected at the same time for 4 weeks. A good correlation was shown [MonoCB∼DiCB : R²=0.8289(p=0.012), TriCB∼HexaCB : R²=0.8388(p<0.0001)] between atmospheric PCBs concentration measured by the LVAS and PUF PAS. The sampling rate of all PCBs isomers showed higher than which were measured by other researchers in different cities. However, trace POPs such as PCBs may involve relatively large analytical errors in measurement, and as a result the air sampling rate of the respective PCB isomer is also likely to involve errors. The method of using a regression straight line between the concentrations obtained by the LVAS and those from the PUF PAS was judged better than the method using the sampling rate, since the former compensated for the experimental errors in the process of evaluation of atmospheric PCBs concentrations using the PUF PAS.

Bioaerosol assessment of indoor air in hospital wards from a tertiary care hospital

Exposure to microorganisms suspended in the air of both occupational and residential indoor environments is associated with a wide range of adverse health effects with major public health impacts. The quality of indoor air is one of the most significant factors affecting the health and well being of people. So the present study was conducted to assess bacteriological and fungal concentration of the indoor air of a teaching tertiary care institute hospital. The present study was carried for a period of three months from June 2018 to August 2018. Air sampling was performed with passive air sampling (settle plate’s methods) according to the 1/1/1 scheme (a Petri dish with a diameter of 9 cm was placed for 1 hour, 1 meter above the floor, and about 1 meter away from the walls). Each ward Petri dishes was exposed for 60 min in the morning and afternoon. Bacteria and fungi was collected on nutrient Agar, Blood Agar and Sabouraud Dextrose Agar(SDA). To obtain the appropriate surface density for counting and to determine the load with respect to time of exposure, the sampling times were set at 60 min in the morning (at 10.00-11.00 AM) and afternoon (2:00-3.00 PM). Both quantitative and qualitative analyses was conducted. The results indicate that the bacterial CFU/m air has been recorded in the range of 65.52 CFU/ m to 1179 CFU/ m at 60 min exposure. The results indicate that the fungal CFU/m air has been recorded in the range no growth to 262 CFU/ m at 60 min exposure. Gram Positive Bacteria were isolated more than Gram Negative Bacteria with predominance of . Whereas, the fungal isolates includes dominance of Candida spp followed by Aspergillus spp. This study revealed that hospital buildings were being ventilated by the aid of natural ventilation system which may increase the possibility of entrance of pollutants from unhygienic external environment. Modern built environment can be a potential source of bioaerosols. Bio-aerosol monitoring in hospitals can be used for tracking of nosocomial infections, identify the source and spread of airborne microorganisms to control hospital associated infections (HAI).

Spatial distribution patterns and human exposure risks of polycyclic aromatic hydrocarbons, organochlorine pesticides and polychlorinated biphenyls in Nepal using tree bark as a passive air sampler

Nepal is abutted between the populated Indo-Gangetic Plain (IGP) and Himalayan mountains. Currently, knowledge on the country-wide distribution and cancer risks of atmospheric organic toxicants in Nepal remains limited. In this study, the concentrations, sources, and distributions of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs), along with their cancer risks, were investigated in Nepal by using tree bark as a passive air sampler. After transferring by a bark/air partitioning model, the averaged concentrations of ∑PAHs, ∑DDTs, ∑HCHs, HCB, ∑Endo and ∑PCBs in the atmosphere of Nepal were 3.71 × 104 pg/m3, 1.10 × 103 pg/m3, 2.92 × 102 pg/m3, 4.38 × 102 pg/m3, 4.66 pg/m3 and 65.8 pg/m3, respectively. Source diagnosis suggested that biomass burning is the major source for PAHs, while local application and long-range transport jointly contribute to the high levels of DDT and HCH in the air. The ILCR (incremental lifetime cancer risk) value was used to assess the risks of various chemicals. Adults have a higher risk than other age groups; the major exposure pathway for risk is by inhalation; and PAHs and HCHs are the dominant chemical classes that lead to risk. It was also found that, in certain hotspots in south Nepal, the carcinogenic risks caused by DDT and HCH were particularly high (>1 × 10−4). Given that illegal and disordered use of legacy POPs in south Nepal and the IGP region is common, our results highlight an urgent need for voluntary regulation of the ongoing use of pesticides.

Monitoring of polycyclic aromatic hydrocarbons using passive air samplers in Seoul, South Korea: Spatial distribution, seasonal variation, and source identification

Abstract Seoul, the capital of South Korea, is one of the largest megacities in northeast Asia. Previous studies have monitored atmospheric polycyclic aromatic hydrocarbons (PAHs) in Seoul, but few have produced highly spatially resolved data. In this study, a total of 144 polyurethane foam-passive air samplers (PUF-PASs) were deployed at 36 sites (4 road, 26 urban, and 6 background sites) in Seoul during the summer of 2016 and the winter of 2017. The concentrations of Σ13 PAHs fell within a range of 2.6–49.9 ng/m3 in summer and 15.5–77.8 ng/m3 in winter. Low-molecular-weight PAHs with 3–4 rings were dominant (accounting for about 97% of all PAHs) at all sampling sites in both seasons compared to high-molecular-weight PAHs with 5–6 rings. Phenanthrene was the most abundant individual compound, accounting for 35–54% and 42–52% of the total PAHs in summer and winter, respectively. The spatial distribution of PAHs was determined by traffic, domestic heating, topography, transport, and meteorological conditions. The concentration of PAHs at the road sites was higher than at the urban and background sites, indicating that vehicular exhaust was a major source in both seasons. In addition, diagnostic ratios and principal component analysis revealed the influence of various sources, such as gasoline and diesel emissions and coal and biomass combustion. Backward air trajectory analysis highlighted the influence of long-range transport from northern China and North Korea during the winter, whereas the influence of local emissions and satellite cities appeared to dominate during the summer. In conclusion, passive air sampling was successfully employed to identify major sources of PAHs in an Asian megacity, indicating that it could produce data with a high spatial resolution for use in human risk assessment and air monitoring networks.

Spatial distribution and seasonal variations of atmospheric organophosphate esters (OPEs) in Tianjin, China based on gridded field observations

The atmospheric concentrations of 14 organophosphate esters (OPEs) were monitored by passive air sampling at 33 sites to determine their spatial distributions, and seasonal variations (summer and winter) in Tianjin, North China. The total concentrations of the OPEs (∑9OPEs) in the summer ranged from 0.08 to 1113 ng/sample with a median of 98.4 ng/sample, which was non-statistically different from the concentrations obtained in the winter (which ranged from 1.93 to 548 ng/sample with a median of 46.2 ng/sample). Among the observed OPEs, the concentrations of TnBP and TCiPP were statistically higher in the summer compared with the winter (p < 0.05). For grouped OPEs, only a significantly higher level of chlorinated OPEs was found in summer than that in winter. In the winter, spatial differences were found to be significantly different between the concentrations of TnBP, TiBP, TCEP, and TEHP in the suburban and rural areas (p < 0.05). Considering the possible point-sources, in the summer, the concentrations of TDCPP, TCiPP, DPEHP, TEHP, and the total concentration of TCPs (denoted as ∑3TCP, comprised of the concentrations of TCP, TmCP, and ToCP) in an electronic-waste (e-waste) dismantling area were higher than those obtained at the other sampling sites. ∑9OPEs at the e-waste site and another site located near a manufacturing plant of organophosphate flame retardants (OFRs) were both higher than the median concentrations obtained at the other sampling sites, and TCiPP was the most abundant pollutant. In the winter, the concentrations of ∑9OPEs at the e-waste site were still higher than their median concentrations at the other sites. Because OPEs are used in aircraft lubricating oils and hydraulic fluids, an airport was thought to be another important source of TiBP and TPhP in the present study. Therefore, the e-waste site, airport, and OFR manufacturing plant may be the major sources of OPEs in the environment.

Monitoring of Airborne Mercury: Comparison of Different Techniques in the Monte Amiata District, Southern Tuscany, Italy.

In the present study, mercury (Hg) concentrations were investigated in lichens (Flavoparmelia caperata (L.) Hale, Parmelia saxatilis (L.) Ach., and Xanthoria parietina (L.) Th.Fr.) collected in the surrounding of the dismissed Abbadia San Salvatore Hg mine (Monte Amiata district, Italy). Results were integrated with Hg concentrations in tree barks and literature data of gaseous Hg levels determined by passive air samplers (PASs) in the same area. The ultimate goal was to compare results obtained by the three monitoring techniques to evaluate potential mismatches. Lichens displayed 180–3600 ng/g Hg, and Hg concentrations decreased exponentially with distance from the mine. Mercury concentration was lower than in Pinus nigra barks at the same site. There was a moderate correlation between Hg in lichen and Hg in bark, suggesting similar mechanisms of Hg uptake and residence times. However, correlation with published gaseous Hg concentrations (PASs) was moderate at best (Kendall Tau = 0.4–0.5, p > 0.05). The differences occurred because a) PASs collected gaseous Hg, whereas lichens and barks also picked up particulate Hg, and b) lichens and bark had a dynamic exchange with the atmosphere. Lichen, bark, and PAS outline different and complementary aspects of airborne Hg content and efficient monitoring programs in contaminated areas would benefit from the integration of data from different techniques.

English

The hospital, even though a place for the sick people, is inhabited by medical staff, administrative, security and patients who may share common microbes in the hospital environment. Some of these organisms may be pathogenic and may pose health hazard to humans through inhalation in the hospital atmosphere. Hence, the objective of this study was to investigate the microbial load of airborne microorganisms in some selected units of the Tamale Teaching Hospital and to suggest possible means to reduce the load. The microbial loads of nine units of the Tamale Teaching Hospital were estimated. Passive air sampling technique, applying open Petri-dishes containing different culture media, was employed to collect sample twice daily for the two seasons witnessed in Ghana. The concentrations of airborne microorganisms in the indoor environment of the wards ranged between 277.61 &ndash; 5395.14 CFU/m3. The statistical analysis showed that the highest bacterial and fungal loads, 5395.14 CFU/m3 and 2021.87 CFU/m3, respectively were recorded in outpatient department (OPD) and the least, 492.37 CFU/m3 and 277.61 CFU/m3, respectively observed in the theatre ward. Staphylococcus aureus, Escherichia coli and Bacillus subtilis were among the bacterial isolates. The fungal isolates include: Aspergillus spp., Alternaria spp., and Fusarium spp. Generally, all units of the hospital harbored very high concentrations of bioaerosols, except the theatre ward. &nbsp; Key words: Indoor air quality, Hospital air quality,, microbial load, open-plate technique, Ghana.

The Use of Polyurethane Foam (PUF) Passive Air Samplers in Exposure Studies to PAHs in Swedish Seafarers

The aim of this study was to test the usefulness of polyurethane foam (PUF) passive air samplers as stationary, and, for the first time, as personal samplers for one week’s sampling period of polycyclic aromatic hydrocarbons (PAHs) in occupational air. Routine monitoring of workplace exposure is commonly performed with active sampling. However, active samplers can sometimes be unsuitable; e.g., it is difficult to make time-integrated measurements, longer than one day, and they can be noisy and obstructive. Indoor air quality on ships is an important aspect of the environment which has not been studied extensively on ships. For seafarers, good indoor air quality becomes particularly important as the ship represents both a working and living environment. In this study, measurements were carried out on two occasions on two different ships, at different workplaces, and for various personnel categories. On each ship, measurements were performed before and after a change of the type of fuel that the ships were operating on. We found a considerable wide range of PAHs exposure levels for the various workplaces and personnel categories on the ships. The stationary measurements, sum 32 PAHs, ranged from 33-39,000 ng m−3 and the personal exposure measurements ranged from 61-8,400 ng m−3. The results point to that the content of PAHs in the fuel can affect the indoor air environment on the entire ship. Further, the results demonstrate that the PUF sampler can serve as a simple and usable screening tool for estimating and tracking point sources of PAHs in micro-environments. Moreover, this study contributes to increased knowledge of exposure to and sources of PAHs for seafarers.

Concurrently Measured Concentrations of Atmospheric Mercury in Indoor (household) and Outdoor Air of Basel, Switzerland.

Indoor air pollution can be a major health risk because urban populations spend up to 90% of their time in closed rooms. Gaseous elemental mercury (GEM) has not been measured as routinely as other indoor air pollutants due to the high costs and limited mobility of active Hg analyzers. However, household GEM concentrations may exceed Hg air quality guidelines as a result of potential indoor GEM sources like broken Hg thermometers. Here we deploy novel low-cost mercury passive air samplers (MerPAS) in 27 households (7 days) and at 14 outdoor locations (29–31 days) in Basel, Switzerland. Average Hg concentrations ranged from 2.0 to 10.8 ng m–3 indoors and from 1.8 to 2.5 ng m–3 outdoors. These results reveal that households are a net source of Hg to the urban atmosphere and exceed outdoor Hg levels by a factor of 2 on average. We estimated an average weekly intake rate of 0.01 μg of Hg/kg of body weight for adult residents in Basel, which is usually lower than Hg exposure of people with dental amalgam fillings. Our campaign demonstrates that air monitoring programs can easily be complemented by straightforward Hg measurements using MerPAS.

Volatile organic compounds in the Spanish National Archaeological Museum: Four years of chemometric analysis

The 19th-century building housing the National Archaeological Museum (MAN) of Spain located in Madrid's downtown was remodelled between 2008 and 2014. During the final of the reform and since its opening to the public on April 2014 and until 2017, the levels of forty different Volatile Organic Compounds (VOCs) were determined and quantified following the AirArt project. This project aimed to identify, quantify and treat the chemical and biological pollutants in the museum. This article discusses the presence, quantification and chemometric studies of the main VOCs identified in the museum. The campaigns were carried out by collecting active and passive air samples on sorbent tubes and monitoring the results over four years. The I/O ratio >1 shows that the indoor VOCs concentrations were higher than those at the outdoors of the museum from the emission of new materials used for their renovation. The Egypt and Reinos Cristianos rooms have the highest I/O ratio. The PCA analysis for four years of indoor and outdoor VOCs analysis of the museum explains the difference between the two environments and highlighted the siloxanes and aldehydes like principal VOCs inside the museum. The concentration of these compounds is below the WHO limits, but little is known about the limit and which compounds can damage the heritage in the museums. The filtration system in the airtight showcase ensures the removal of pollutants over time, avoiding damage to both the health of conservatives and the heritage on display.

Dynamic Transmission of Staphylococcus Aureus in the Intensive Care Unit.

Staphylococcus aureus is an important bacterial pathogen. This study utilized known staphylococcal epidemiology to track S. aureus between patients, surfaces, staff hands and air in a ten-bed intensive care unit (ICU). Methods: Patients, air and surfaces were screened for total colony counts and S. aureus using dipslides, settle plates and an MAS-100 slit-sampler once a month for 10 months. Data were modelled against proposed standards for air and surfaces, and ICU-acquired staphylococcal infection. Whole-cell genomic typing (WGS) demonstrated possible transmission pathways between reservoirs. Results: Frequently touched sites were more likely to be contaminated (>12 cfu/cm2; p = 0.08). Overall, 235 of 500 (47%) sites failed the surface standard (≤2.5 cfu/cm2); 20 of 40 (50%) passive air samples failed the “Index of Microbial Air” standard (2 cfu/9 cm plate/h), and 15/40 (37.5%) air samples failed the air standard (<10 cfu/m3). Settle plate data were closer to surface counts than automated air data; the surface count most likely to reflect pass/fail rates for air was 5 cfu/cm2. Surface counts/bed were associated with staphylococcal infection rates (p = 0.012). Of 34 pairs of indistinguishable S. aureus, 20 (59%) showed autogenous transmission, with another four (12%) occurring between patients. Four (12%) pairs linked patients with hand-touch sites and six (18%) linked airborne S. aureus, staff hands and hand-touch sites. Conclusion: Most ICU-acquired S. aureus infection is autogenous, while staff hands and air were rarely implicated in onward transmission. Settle plates could potentially be used for routine environmental screening. ICU staphylococcal infection is best served by admission screening, systematic cleaning and hand hygiene.

Home Assessment of Indoor Microbiome (HAIM) in Relation to Lower Respiratory Tract Infections among Under-Five Children in Ibadan, Nigeria: The Study Protocol.

The association between household air pollution and lower respiratory tract infections (LRTI) among children under five years of age has been well documented; however, the extent to which the microbiome within the indoor environment contributes to this association is uncertain. The home assessment of indoor microbiome (HAIM) study seeks to assess the abundance of indoor microbiota (IM) in the homes of under-five children (U-5Cs) with and without LRTI. HAIM is a hospital- and community-based study involving 200 cases and 200 controls recruited from three children’s hospitals in Ibadan, Nigeria. Cases will be hospital-based patients with LRTI confirmed by a pediatrician, while controls will be community-based participants, matched to cases on the basis of sex, geographical location, and age (±3 months) without LRTI. The abundance of IM in houses of cases and controls will be investigated using active and passive air sampling techniques and analyzed by qualitative detection of bacterial 16SrRNA gene (V3–V4), fungal ITS1 region, and viral RNA sequencing. HAIM is expected to elucidate the relationship between exposure to IM and incidence of LRTI among U-5Cs and ultimately provide evidence base for strategic interventions to curtail the burgeoning burden of LRTI on the subcontinent.

Elevated Concentrations of Semivolatile Organic Compounds in Social Housing Multiunit Residential Building Apartments

Flame retardants and phthalates are commonly used in consumer products and building materials, and as such, are prevalent in indoor air. Polycyclic aromatic hydrocarbons (PAHs) can have both indoor and outdoor sources and can also be found in indoor air. Flame retardants, phthalates, and PAHs were measured in indoor air in 71 units in low-income social housing multi-unit residential buildings (MURBs) using silicone rubber (polydimethylsiloxane or PDMS) passive air samplers deployed for 1 week in Toronto, Canada, in late spring and winter of 2017. Tris(1,3-dichloro-2-propyl) phosphate (TDCiPP), diethyl phthalate (DEP), and phenanthrene were the dominate flame retardant, phthalate, and PAH, with median concentrations of 1640 pg/m3 and 1840 and 79.0 ng/m3, respectively. Flame retardant and phthalate concentrations were 2 to 18 times higher than those in predominantly detached and semi-detached houses in Toronto measured using the same passive samplers. These results indicate higher exposures among residents of low-income social housing (63% with income <$23,400) than those of higher socio-economic status single-family dwellings (67% with income >$100,000).

Spatially high-resolved monitoring and risk assessment of polycyclic aromatic hydrocarbons in an industrial city

Polycyclic aromatic hydrocarbons (PAHs) were monitored at 20 sites in semi-rural, urban, and industrial areas of Ulsan, the largest industrial city in South Korea, for one year. The target compounds were the 16 priority PAHs designated by the US Environmental Protection Agency except for naphthalene, acenaphthene, and acenaphthylene. Gaseous PAHs collected using polyurethane foam-based passive air samplers (PUF-PASs) and particulate PAHs predicted using gas/particle partitioning models were used to estimate the human health risks. The mean total cancer risk through inhalation intake and dermal absorption for all target age groups (children, adolescents, adults, and lifetime) ranged from 0.10 × 10-7 to 2.62 × 10-7, lower than the acceptable risk level (10-6), thus representing a safe level for residents. The cancer risk through dermal absorption and inhalation intake was predicted to be highest in winter, mostly due to the higher concentrations of PAHs, especially high-molecular-weight species with greater toxicity. Additionally, gaseous and particulate PAHs contributed more to dermal absorption and inhalation intake, respectively. As a consequence of local emissions and advection, the risks were higher in the industrial and semi-rural areas. This study suggests that human health risks can be cost-effectively mapped on a local scale using passive air sampling.

Determination of dry deposition velocity of polycyclic aromatic hydrocarbons under the sub-tropical climate and its implication for regional cycling

Atmospheric dry deposition is a major pathway for removal of polycyclic aromatic hydrocarbons (PAHs) from the atmosphere. Despite its significance in the atmospheric environment, measurements of the dry deposition velocity (VDD) and deposition fluxes (FDD) of PAHs are relatively limited. In this study, a passive dry deposition (PAS-DD) collector was co-deployed with passive air sampler polyurethane foam (PAS-PUF) from November 2015 to November 2016 in two major cities (Kathmandu and Pokhara), Nepal, to investigate the VDD and FDD of PAHs. The VDD of PAHs ranged from 0.25 to 0.5 cm s−1 and the annual average was recorded as 0.37 ± 0.08 cm s−1. On the basis of measured VDD, the FDD of ∑15PAHs in Kathmandu and Pokhara were estimated as 66 and 5 kg yr−1 respectively. According to the measured VDD of Kathmandu and Pokhara in this study, and the previously published VDD data of Toronto, Canada, where the same PAS-DD collector was used, a significant multi-linear correlation (r2 = 0.79, p < 0.05) was found between VDD of higher molecular weight (HMW with MW ≥ 228.3 and ≥ 4 rings) PAHs and meteorological parameters (precipitation and wind speed) and vapor pressure of PAHs. To the best of our knowledge, this enabled the development of an empirical model that can exhibit the combined effects of meteorological conditions on the VDD of HMW PAHs. The model was used to estimate the VDD values for major cities in the Indo-Gangetic Plain (IGP) region and the maximum estimated proportion of HMW PAHs deposited by dry deposition reached up to 60% of total emissions. Although PAH emissions in the IGP region pose global risks, the results of this study highlight the considerable risk for local IGP residents, due to the large dry deposition proportion of HMW PAHs.

Passive monitoring techniques to evaluate environmental pesticide exposure: Results from the Infant's Environmental Health study (ISA)

BackgroundPesticides used in agriculture may expose populations living nearby. Costa Rica is a major banana-exporting country, its production depends on extensive pesticide use. ObjectivesTo evaluate environmental pesticide exposure, we measured levels of current-use pesticides in air and dust from 12 schools in Matina County, Costa Rica, with passive sampling methods. MethodsWe selected ten proximal and two non-proximal schools and placed polyurethane foam passive air samplers outdoors at each school, during four consecutive periods. At three of these schools, we also placed an active air sampler during the first 24 h of each sampling period. We collected passive dust samples by placing a glass Petri Dish at the inside of each school. We subsequently performed a chemical analysis of 18 pesticides, using gas chromatography with mass detector. ResultsWith passive air samplers we detected ten different pesticides: two insecticides, two nematicides, and six fungicides, of which nine reported to be used on banana plantations. More than half of the samples contained at least five pesticides. Chlorpyrifos was detected most-frequently, in 98% of samples, followed by the nematicides etoprophos and the fungicide pyrimethanil that were both detected in 81% of samples. Chlorpyrifos concentrations were five times higher in proximal as compared to non-proximal schools: mean = 18.2 ng/m3 (range = 6.1–36.1) and mean = 3.5 ng/m3 (range= <0.5–11.4) and varied more between schools than in time (intra-class correlation coefficient = 0.80). In general, results from passive and active samplers showed similar exposure patterns; yet median concentrations tended to be higher in passive samplers. In dust samples, mostly fungicides were detected; chlorothalonil was detected most frequently, in 50% of samples. DiscussionPassive air sampling is a promising technique to characterize environmental exposure to current-use pesticides; more studies are needed to characterize the sampling rates, reproducibility and optimum sampling times for passive samplers. School environments near banana plantations are contaminated with multiple pesticides that include insecticides, nematicides, and fungicides, which is of concern.