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Organophosphate esters (OPEs) have been detected in the Arctic environment, but the influence of glacial melt on the environmental behavior of OPEs in recipient Arctic aquatic ecosystems is still unknown. In this study, water samples were collected from Lake Hazen (LH) and its tributaries to investigate the distribution of 14 OPEs in LH and to explore the input of OPEs from glacial rivers to LH and the output of OPEs from LH in 2015 and 2018. Σ14OPE concentrations in water of LH were lower than glacial rivers and its outflow, the Ruggles River. In 2015, a high melt year, we estimated that glacial rivers contributed 7.0 ± 3.2 kg OPEs to LH, compared to a 16.5 ± 0.3 kg OPEs output by the Ruggles River, suggesting that residence time and/or additional inputs via direct wet and dry deposition and permafrost melt likely result in OPE retention in the LH watershed. In 2018, a lower melt year, Σ14OPE concentrations in glacial rivers were much lower, indicating that the rate of glacier melt may govern, in part, the concentrations of OPEs in the tributaries of LH. This study highlights long-range transport of OPEs, their deposition in Arctic glaciers, landscapes, and lakes.

The delivery of perfluoroalkyl substances (PFAS) from snowpacks into Lake Hazen, located on Ellesmere Island (Nunavut, Canada, 82° N) indicates that annual atmospheric deposition is a major source of PFAS that undergo complex cycling in the High Arctic. Perfluoroalkyl carboxylic acids (PFCA) in snowpacks display odd-even concentration ratios characteristic of long-range atmospheric transport and oxidation of volatile precursors. Major ion analysis in snowpacks suggests that sea spray, mineral dust, and combustion aerosol are all relevant to the fate of PFAS in the Lake Hazen watershed. Distinct drifts of light and dark snow (enriched with light absorbing particles, LAPs) facilitate the study of particle loads on the fate of PFAS in the snowpack. Total PFAS (ΣPFAS, ng m-2) loads are lower in snowpacks enriched with LAPs and are attributed to reductions in snowpack albedo combined with enhanced post-depositional melting. Elevated concentrations of PFCA are observed in the top 5 m of the water column during snowmelt periods compared to ice-covered or ice-free periods. PFAS concentrations in deep waters of the Lake Hazen water column were consistent between snowmelt, ice-free, and ice-covered periods, which is ascribed to the delivery of dense and turbid glacier meltwaters mixing PFAS throughout the Lake Hazen water column. These observations highlight the underlying mechanisms in PFAS cycling in High Arctic Lakes particularly in the context of increased particle loads and melting.

Nitrous acid (HONO) is a reservoir of NOx and an emerging pollutant having direct impacts on air quality, both in- and outdoors, as well as on human health. In this work, the amine-functionalized metal–organic framework (MOF), UiO-66-NH2, was investigated due to its potential to selectively decontaminate nitrous acid at environmentally relevant concentrations. UiO-66-NH2 proved to be effective in the removal of nitrous acid from a continuous gaseous stream. This is observed via the formation of an aryl diazonium salt that subsequently converts to a phenol with a concomitant release of nitrogen gas. This process is preceded via the formation of the nitrosonium cation (likely protonation from an acidic proton on the node). Thus, UiO-66-NH2 is capable of selectively converting the pollutant nitrous acid to benign products.

Traditional cooking using biomass is associated with ill health, local environmental degradation, and regional climate change. Clean stoves (liquefied petroleum gas (LPG), biogas, and electric) are heralded as a solution, but few studies have demonstrated their environmental health benefits in field settings. We analyzed the impact of mainly biogas (as well as electric and LPG) stove use on social, environmental, and health outcomes in two districts in Odisha, India, where the Indian government has promoted household biogas. We established a cross-sectional observational cohort of 105 households that use either traditional mud stoves or improved cookstoves (ICS). Our multidisciplinary team conducted surveys, environmental air sampling, fuel weighing, and health measurements. We examined associations between traditional or improved stove use and primary outcomes, stratifying households by proximity to major industrial plants. ICS use was associated with 91% reduced use of firewood (p0.01), substantial time savings for primary cooks, a 72% reduction in PM

Perfluoroalkyl substances (PFASs) are synthetic environmentally-persistent pollutants that are amenable to long-range transport and accumulation in remote Arctic ecosystems. In this study, historical inventories of twenty-three PFASs (i.e. C4-C14, C16 perfluoroalkane carboxylic acids (PFCAs); C4, C6-C8, C10 perfluoroalkane sulfonic acids (PFSAs); perfluoro-4-ethyl-cyclohexane sulfonic acid (PFECHS); dodecafluoro-3H-4,8-dioxanonanoic acid (ADONA); 8-chloro-perfluoro-1-octane sulfonic acid (8-Cl-PFOS); chlorinated polyfluorinated ether sulfonic acids (Cl-PFESAs) including 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (6:2 Cl-PFESA) and 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (8:2 Cl-PFESA); as well as perfluorooctane sulfonamide (FOSA)) are determined in two intact sediment cores collected from Lake Hazen, located in northern Ellesmere Island at 82° N in 2012 and Lake B35, located in central Nunavut at 64° N in 2009. In Lake Hazen, fluxes of perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), perfluorobutane sulfonic acid (PFBS), and perfluorooctane sulfonic acid (PFOS) increased during 1963-2011. In Lake B35, fluxes of perfluoroheptanoic acid (PFHpA), PFOA, perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUnDA) increased during 1952-2009. The temporal trends for PFASs in Lake Hazen and Lake B35 sediments are consistent with the continuous annual delivery of PFASs to the Arctic of Canada. Temporal trends in sediment cores appear to follow historical market changes in PFAS manufacturing inventory. The doubling time of PFAS fluxes are faster in Lake Hazen sediments than Lake B35 sediments. In Lake Hazen, this may be attributed to the enhanced delivery of sediment and historically-archived PFASs promoted by climate-induced glacier melting in the Lake Hazen watershed post-2005. Exponentially increasing PFAS temporal trends in High and Low Arctic lakes in Canada stress the importance of developing effective global regulatory policies for PFAS manufacturing and highlights the potential for climate change-induced contaminant release from melting glaciers in the Arctic.

To improve understanding of long-range transport of perfluoroalkyl substances to the High Arctic, samples were collected from a snow pit on the Devon Ice Cap in spring 2008. Snow was analyzed for perfluoroalkyl acids (PFAAs), including perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs), as well as perfluorooctane sulfonamide (FOSA). PFAAs were detected in all samples dated from 1993 to 2007. PFAA fluxes ranged from

An inability to produce environmentally relevant gaseous mixing ratios of perfluoroalkyl acids (PFAAs), ubiquitous global contaminants, limits the analytical reliability of atmospheric chemists to make accurate gas and particulate measurements that are demonstrably free of interferences due to sampling artefacts. A gas phase source for PFAAs based on the acid displacement mechanism using perfluoropropionate (PFPrA), perfluorobutanoate (PFBA), perfluorohexanoate (PFHxA), and perfluorooctanoate (PFOA) has been constructed. The displacement efficiency of gas phase perfluorocarboxylic acids (PFCAs) is inversely related to chain length. Decreasing displacement efficiencies for PFPrA, PFBA, PFHxA, and PFOA were 90% ± 20%, 40% ± 10%, 40% ± 10%, 9% ± 4%, respectively. Generating detectable amounts of gas phase perfluorosulfonic acids (PFSAs) was not possible. It is likely that lower vapour pressure and much higher acidity play a role in this lack of emission. PFCA emission rates were not elevated by increasing relative humidity (25%-75%), nor flow rate of carrier gas from 33-111 sccm. Overall, reproducible gaseous production of PFCAs was within the error of the production of hydrochloric acid (HCl) as a displacing acid (±20%) and was accomplished using a dry nitrogen flow of 33 ± 2 sccm. A reproducible mass emission rate of 0.97 ± 0.10 ng min(-1) (n = 8) was observed for PFBA. This is equivalent to an atmospheric mixing ratio of 12 ppmv, which is easily diluted to environmentally relevant mixing ratios of PFBA. Conversely, generating gas phase perfluorononanoic acid (PFNA) by sublimating the solid acid under the same conditions produced a mass emission rate of 2800 ng min(-1), which is equivalent to a mixing ratio of 18 ppthv and over a million times higher than suspected atmospheric levels. Thus, for analytical certification of atmospheric sampling methods, generating gas phase standards for PFCAs is best accomplished using acid displacement under dry conditions. This yields quickly stabilized, reproducible emissions and mixing ratios that are easily diluted to environmentally relevant levels. Gas phase PFBA from this source has also been shown to be quantitatively collected using an annular denuder coated with sodium carbonate (Na2CO3) according to Environmental Protection Agency (EPA) method Compendium I.O-4.2. Overall, producing gas phase PFAAs at constant atmospherically-relevant levels will enable the development of standard approaches in certifying gas and particle collection efficiencies for instruments interrogating the gas-particle partitioning and long-range transport of PFCAs in the atmosphere.