Polyurethane Foam Disk Passive Samplers Research Articles

Ambient air concentrations and risk assessment of selected organochlorine pesticides (OCPs) across five Middle Eastern countries

This paper presents data obtained from concurrently deployed polyurethane foam disk passive samplers in Kuwait, Turkey, Lebanon, Saudi Arabia, and Oman between January and October 2018. The study’s main goal was to initiate a passive air sampling network across the Middle East to generate comparable data, which will help report obligations of the various countries and be used in protocol discussions. The ∑24OCP concentrations were highest in the samples collected from Kartaba in Lebanon (7780 pg·m-3), and the lowest concentration was recorded at the BUTAL site in the Bursa province of Turkey (7.27 pg·m-3). The mean ambient ∑24OCP concentrations on a country-specific basis over consecutive sampling campaigns were: Lebanon (1680 pg·m-3) > Bursa (Turkey) (78.7 pg·m-3) > Oman (55 pg·m-3) > Kuwait (42 pg·m-3) > Jeddah, Saudi Arabia (19.1 pg·m-3). The results show no cancer risk due to inhalation of organochlorine pesticides (OCPs) in ambient air. This study provides the first reliable measurements of the spatial variability in the atmospheric concentrations of OCPs across several Middle Eastern countries, providing a baseline for assessing time trends in air, one of the core matrices for the effectiveness evaluation of the Stockholm Convention on Persistent Organic Pollutants.

Polyurethane foam disk passive sampler derived air concentrations of persistent organic pollutants in an agricultural region with hot climate

Polyurethane foam (PUF) disks passive air samplers were deployed in an agricultural region with hot climate to determine atmospheric concentrations of 22 organochlorine pesticides (OCPs) and 15 polychlorinated biphenyls (PCBs). Sampling rates (2.39–15.9 m3.day−1) increased with rising ambient air temperatures. Total OCP and PCB concentrations were 0.884–97.0 pg.m−3 and nd-213 pg.m−3, respectively. The most prominent OCPs in the samples were hexachlorocyclohexane (HCH) isomers, chlordane compounds, dichlorodiphenyltrichloroethane (DDT) derivatives, and endosulfan isomers. The isomer ratios of DDT and Chlordane in the samples indicated older usage while endosulfan ratios showed recent input of technical endosulfan in the region. Total PCB levels were dominated by low chlorinated congeners. The contaminant levels in air samples were mainly lower or similar by comparison to other studies conducted at agricultural regions worldwide. Although the production and use of these chemicals have been banned, results of this study show that some of the chemicals could still be found in agricultural areas. Presence of these chemicals in environmental samples may be result of the degradation of formerly used chemicals, atmospheric transport or illegal use of banned chemicals.

Using long-term air monitoring of semi-volatile organic compounds to evaluate the uncertainty in polyurethane-disk passive sampler-derived air concentrations

Much effort has been made to standardise sampling procedures, laboratory analysis, data analysis, etc. for semi volatile organic contaminants (SVOCs). Yet there are some unresolved issues in regards to comparing measurements from one of the most commonly used passive samplers (PAS), the polyurethane foam (PUF) disk PAS (PUF-PAS), between monitoring networks or different studies. One such issue is that there is no universal means to derive a sampling rate (Rs) or to calculate air concentrations (Cair) from PUF-PAS measurements for SVOCs. Cair was calculated from PUF-PAS measurements from a long-term monitoring program at a site in central Europe applying current understanding of passive sampling theory coupled with a consideration for the sampling of particle associated compounds. Cair were assessed against concurrent active air sampler (AAS) measurements. Use of “site-based/sampler-specific” variables: Rs, calculated using a site calibration, provided similar results for most gas-phase SVOCs to air concentrations derived using “default” values (commonly accepted Rs). Individual monthly PUF-PAS-derived air concentrations for the majority of the target compounds were significantly different (Wilcoxon signed-rank (WSR) test; p < 0.05) to AAS regardless of the input values (site/sampler based or default) used to calculate them. However, annual average PUF-PAS-derived air concentrations were within the same order of magnitude as AAS measurements except for the particle-phase polycyclic aromatic hydrocarbons (PAHs). Underestimation of PUF-derived air concentrations for particle-phase PAHs was attributed to a potential overestimation of the particle infiltration into the PUF-PAS chamber and underestimation of the particle bound fraction of PAHs.

Stability of polycyclic aromatic compounds in polyurethane foam-type passive air samplers upon O3 exposure

Stability of polycyclic aromatic compounds (PACs) in polyurethane foam (PUF) disks upon O3 exposure was studied in a flow tube. A wide range of PACs was evaluated by spiking PUF disks with PACs and exposing to O3 at concentrations that were equivalent to two months exposure, a typical deployment period for these passive air samplers. Ambient concentrations of O3 (∼50 ppb) at 0% and 50% relative humidity (RH) were applied. At 0% RH, 23 of 68 PACs yielded more than 50% loss after exposure. The mean percent loss was 30% with perylene and 9,10-dimethylanthracene the most reactive polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs, respectively. At 50% RH, 77% of the studied PACs was stable upon O3 exposure (PACexposed/PACunexposed > 0.7). The mean percent loss was 17% and only 7 of 68 PACs yielded greater than 50% loss. In general, the reactivity of most of the PACs decreased at higher RH, except for the reactive PAHs (acenaphthylene, 2,3-dimethylanthracene, 9,10-dimethylanthracene, dibenzothiophene, and 2-methyldibenzothiophene) which demonstrated lower RH dependence. The experimental conditions in this study represent a worst case scenario for the stability of PACs sorbed to PUF. In reality, the sampling of PACs in ambient air represents an ‘aged’ component of PACs where the most reactive species have already partially been removed. Also, PACs in ambient air will be associated with the particle phase to varying extents that will help to enhance their stability. Therefore, under regular operating conditions, over a 2-month exposure, we expect a minimal error in the measurement of total concentration of PACs in air using the PUF disk passive sampler.

Using PUF disk passive samplers to simultaneously measure air concentrations of persistent organic pollutants (POPs) across the Tuscany Region, Italy

Passive air samplers consisting of polyurethane foam (PUF) disks were deployed simultaneously over 2–4 month periods from April to July 2008 at 19 locations throughout the Tuscany Region at urban (n=9), rural (n=7) and agricultural sites (n=3). The purpose of the study was to assess the gas–phase air concentrations of PCBs, OCPs, PBDEs and PAHs on a local and regional scale. Derived air concentrations (pg m−3) ranged from below detection limit (BDL) to 300 for Σ6PCBs and from BDL to 30 for Σ3PBDEs. As expected, the highest PCB concentrations (pg m−3) were observed at urban sites, peaking in Piombino (300). PBDEs, however, exhibited a “reverse gradient” (i.e. rural>agricultural>urban) with highest air concentration at the rural site, Arcidoso (30). Levels of OCPs showed less distinct differences among the three site types. The most frequently detected OCPs were Endosulfan I, γ–HCH and α–HCH. Endosulfan I ranged from BDL to 2 200pg m−3, α–HCH from BDL to 610, and γ–HCH from BDL to 1 100. The high air concentrations of HCHs were surprising and possibly due to continued and illegal use – especially at agricultural and urban sites that exhibited the highest levels in air. PAHs showed highest concentrations (pg m−3) at agricultural and urban sites, ranging from 290 to 4 700 and were generally consistent with other data sets from Europe. PAHs were dominated by the 3–ring PAHs (76±6)%, with phenanthrene alone accounting for (45±11%) of the total PAHs. This study demonstrates the feasibility of using PUF disks as time–integrating passive air samplers for assessing local and regional scale concentrations of a wide range of POPs in central Italy. Given their low cost and simplicity, passive air samplers are the preferred option for conducting concurrent sampling at multiple sites for monitoring and research purposes.