Uncertainties in global aerosols and climate effects due to biofuel emissions

Aerosol emissions from biofuel combustion impact both health and climate; however, while reducing emissions through improvements to combustion technologies will improve health, the net effect on climate is largely unconstrained. In this study, we examine sensitivities in global aerosol concentration, direct radiative climate effect, and cloud-albedo aerosol indirect climate effect to uncertainties in biofuel emission factors, optical mixing state, and model nucleation and background secondary organic aerosol (SOA). We use the Goddard Earth Observing System global chemical-transport model (GEOS-Chem) with TwO Moment Aerosol Sectional (TOMAS) microphysics. The emission factors include amount, composition, size, and hygroscopicity, as well as optical mixing-state properties. We also evaluate emissions from domestic coal use, which is not biofuel but is also frequently emitted from homes. We estimate the direct radiative effect assuming different mixing states (homogeneous, core-shell, and external) with and without absorptive organic aerosol (brown carbon). We find the global-mean direct radiative effect of biofuel emissions ranges from −0.02 to +0.06 W m−2 across all simulation/mixing-state combinations with regional effects in source regions ranging from −0.2 to +0.8 W m−2. The global-mean cloud-albedo aerosol indirect effect (AIE) ranges from +0.01 to −0.02 W m−2 with regional effects in source regions ranging from −1.0 to −0.05 W m−2. The direct radiative effect is strongly dependent on uncertainties in emissions mass, composition, emissions aerosol size distributions, and assumed optical mixing state, while the indirect effect is dependent on the emissions mass, emissions aerosol size distribution, and the choice of model nucleation and secondary organic aerosol schemes. The sign and magnitude of these effects have a strong regional dependence. We conclude that the climate effects of biofuel aerosols are largely unconstrained, and the overall sign of the aerosol effects is unclear due to uncertainties in model inputs. This uncertainty limits our ability to introduce mitigation strategies aimed at reducing biofuel black carbon emissions in order to counter warming effects from greenhouse gases. To better understand the climate impact of particle emissions from biofuel combustion, we recommend field/laboratory measurements to narrow constraints on (1) emissions mass, (2) emission size distribution, (3) mixing state, and (4) ratio of black carbon to organic aerosol

Exposure to Household Air Pollution from Biomass-Burning Cookstoves and HbA1c and Diabetic Status Among Honduran Women

Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middle‐income countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This cross‐sectional study of 142 women (72 with traditional stoves and 70 with cleaner‐burning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24‐hour average kitchen and personal fine particulate matter [PM2.5] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84 μg/m3 increase in personal PM2.5, 1.49; 95% confidence interval [CI], 1.11‐2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated

Exposure to Household Air Pollution from Biomass Cookstoves and Blood Pressure Among Women in Rural Honduras: A Cross‐Sectional Study

Growing evidence links household air pollution exposure from biomass cookstoves with elevated blood pressure. We assessed cross‐sectional associations of 24‐hour mean concentrations of personal and kitchen fine particulate matter (PM2.5), black carbon (BC), and stove type with blood pressure, adjusting for confounders, among 147 women using traditional or cleaner‐burning Justa stoves in Honduras. We investigated effect modification by age and body mass index. Traditional stove users had mean (standard deviation) personal and kitchen 24‐hour PM2.5 concentrations of 126 μg/m3 (77) and 360 μg/m3 (374), while Justa stove users’ exposures were 66 μg/m3 (38) and 137 μg/m3(194), respectively. BC concentrations were similarly lower among Justa stove users. Adjusted mean systolic blood pressure was 2.5 mm Hg higher (95% CI, 0.7‐4.3) per unit increase in natural log‐transformed kitchen PM2.5 concentration; results were stronger among women of 40 years or older (5.2 mm Hg increase, 95% CI, 2.3‐8.1). Adjusted odds of borderline high and high blood pressure (categorized) were also elevated (odds ratio = 1.5, 95% CI, 1.0‐2.3). Some results included null values and are suggestive. Results suggest that reduced household air pollution, even when concentrations exceed air quality guidelines, may help lower cardiovascular disease risk, particularly among older subgroups

Assessment of Nonoccupational Exposure to DDT in the Tropics and the North: Relevance of Uptake via Inhalation from Indoor Residual Spraying

Ba c k g r o u n d: People who live in dwellings treated with indoor residual spraying (IRS) of DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] for disease–vector control in the tropics and indig-enous populations in the Arctic who comsume marine mammals experience high nonoccupational exposure to DDT. Although the use of DDT in IRS is rising, the resulting nonoccupational expo-sure is poorly characterized. ob j e c t i v e s: We have provided a comparative assessment of exposure to DDT and its metabolites in the general population of the tropical and northern regions and in highly exposed populations in these regions. Me t h o d s: We compiled > 600 average or median DDT concentrations from the peer-reviewed literature, representing > 23,000 individual measurements in humans, food, air, soil, and dust. We use Monte Carlo sampling of distributions based on these data to estimate distributions of population- and route-specific uptake. We evaluate our exposure estimates by comparing them with biomonitoring data .re s u l t s: DDT concentrations are highest in people living in IRS-treated houses and lowest in the northern general population, differing by a factor of about 60. Inuits and the general population in the tropics have similar concentrations. Inhalation exposure explains most of the difference in concentration between the highly exposed and the general population in the Tropics. Calculated exposure levels are consistent with human biomonitoring data. co n c l u s i o n s: Nonoccupational inhalation exposure is a relevant exposure pathway for people living in homes treated by IRS of DDT. Continued monitoring of time trends and DDE to DDT ratios in the Tropics and in the North is needed to identify a possible slowdown in concentration decline and the influence of ongoing DDT use.ISSN:1552-9924ISSN:0091-676

Dataset associated with "Unequal airborne exposure burden to toxic metals is associated with race, ethnicity, and segregation"

This dataset contains annual and county-level mean concentrations and mass proportions of fine particulate metals (aggregated from the EPA's CSN/IMPROVE networks), associated minimum detectable limit for each monitor, as well as racial and ethnic demographic population data. This dataset is aggregated from publicly available air pollutant data from the EPA (http://views.cira.colostate.edu/fed/QueryWizard/Default.aspx) and the US Census Bureau (https://data.census.gov/cedsci/). This dataset is used to examine the association of racial residential segregation with fine particulate metal concentrations. The time period ranges from year 2009 to 2019.- Columns labeled "XX_concentration" report the annual and county-level mean concentration in ug m-3 - Columns labeled 'XX_content" report the mass proportion of fine particulate metals relative to PM2.5 mass - Columns labeled "XX_mdl" report the minimum detectable limit for that species at that monitor. In the case of more than one monitor in the county, this column reports the average. - Columns labeled "DI_XX" report the dissimilarity index for the racial/ethnic group using the non-Hispanic White population as the reference population (see associated manuscript for details), where "NHB" corresponds to non-Hispanic Black and "native_amer" to "Native American". - Columns labeled "XX_pop_county" report the county population of the respective racial/ethnic group. These groupings reflect the identification made by individuals in US Census Bureau data. "NHW" refers to "non-Hispanic White". - "CountyFIPS" refers to the county FIPS code. - "Latitude" and "Longitude" reflect the coordinates of the monitor in degrees. In the case of more than one monitor per county, these columns averages.Communities of color have been exposed to a disproportionate burden of air pollution across the United States for decades. Yet, the inequality in exposure to known toxic elements of air pollution is unclear. Here, we find that populations living in racially segregated communities are exposed to a form of fine particulate matter with over three times higher mass proportions of known toxic and carcinogenic metals. While concentrations of total fine particulate matter are two times higher in racially segregated communities, concentrations of metals from anthropogenic sources are nearly ten times higher. Populations living in racially segregated communities have been disproportionately exposed to these environmental stressors throughout the past decade. We find evidence, however, that these disproportionate exposures may be abated though targeted regulatory action. For example, recent regulations on marine fuel oil not only reduced vanadium concentrations in coastal cities, but also sharply lessened differences in vanadium exposure by segregation.This work was supported financially by grants from the Health Effects Institute under grant number 4953- RFA14-3/16-4 awarded to FD, National Institute of Health under grant numbers DP2MD012722 and P50MD010428 awarded to FD, National Institute of Health and National Institute of Environmental Health Sciences under grant number R01 ES028033 awarded to FD, National Institute of Health and Columbia University under grant number 1R01ES030616 awarded to FD, the National Institute On Minority Health And Health Disparities of the National Institutes of Health under award number R01MD012769 awarded to MLB and FD, the Environmental Protection Agency under grant number 83587201-0 awarded to FD and grant number RD83587101 awarded to MLB, The Climate Change Solutions Fund, and the Harvard Star Friedman Award. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the Environmental Protection Agency

Exposure to Household Air Pollution from Biomass Cookstoves and Levels of Fractional Exhaled Nitric Oxide (FeNO) among Honduran Women

Household air pollution is estimated to be responsible for nearly three million premature deaths annually. Measuring fractional exhaled nitric oxide (FeNO) may improve the limited understanding of the association of household air pollution and airway inflammation. We evaluated the cross-sectional association of FeNO with exposure to household air pollution (24-h average kitchen and personal fine particulate matter and black carbon; stove type) among 139 women in rural Honduras using traditional stoves or cleaner-burning Justastoves. We additionally evaluated interaction by age. Results were generally consistent with a null association; we did not observe a consistent pattern for interaction by age. Evidence from ambient and household air pollution regarding FeNO is inconsistent, and may be attributable to differing study populations, exposures, and FeNO measurement procedures (e.g., the flow rate used to measure FeNO)

Detection of Viruses from Bioaerosols Using Anion Exchange Resin

This protocol demonstrates a customized bioaerosol sampling method for viruses. In this system, anion exchange resin is coupled with liquid impingement-based air sampling devices for efficacious concentration of negatively-charged viruses from bioaerosols. Thus, the resin serves as an additional concentration step in the bioaerosol sampling workflow. Nucleic acid extraction of the viral particles is then performed directly from the anion exchange resin, with the resulting sample suitable for molecular analyses. Further, this protocol describes a custom-built bioaerosol chamber capable of generating virus-laden bioaerosols under a variety of environmental conditions and allowing for continuous monitoring of environmental variables such as temperature, humidity, wind speed, and aerosol mass concentration. The main advantage of using this protocol is increased sensitivity of viral detection, as assessed via direct comparison to an unmodified conventional liquid impinger. Other advantages include the potential to concentrate diverse negatively-charged viruses, the low cost of anion exchange resin (~$0.14 per sample), and ease of use. Disadvantages include the inability of this protocol to assess infectivity of resin-adsorbed viral particles, and potentially the need for the optimization of the liquid sampling buffer used within the impinger

Exposure to household air pollution from biomassâ burning cookstoves and HbA1c and diabetic status among Honduran women

Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middleâ income countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This crossâ sectional study of 142 women (72 with traditional stoves and 70 with cleanerâ burning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24â hour average kitchen and personal fine particulate matter [PM2.5] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84 μg/m3 increase in personal PM2.5, 1.49; 95% confidence interval [CI], 1.11â 2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145588/1/ina12484_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145588/2/ina12484.pd

Exposure to household air pollution from biomass cookstoves and blood pressure among women in rural Honduras: A crossâ sectional study

Growing evidence links household air pollution exposure from biomass cookstoves with elevated blood pressure. We assessed crossâ sectional associations of 24â hour mean concentrations of personal and kitchen fine particulate matter (PM2.5), black carbon (BC), and stove type with blood pressure, adjusting for confounders, among 147 women using traditional or cleanerâ burning Justa stoves in Honduras. We investigated effect modification by age and body mass index. Traditional stove users had mean (standard deviation) personal and kitchen 24â hour PM2.5 concentrations of 126 μg/m3 (77) and 360 μg/m3 (374), while Justa stove usersâ exposures were 66 μg/m3 (38) and 137 μg/m3 (194), respectively. BC concentrations were similarly lower among Justa stove users. Adjusted mean systolic blood pressure was 2.5 mm Hg higher (95% CI, 0.7â 4.3) per unit increase in natural logâ transformed kitchen PM2.5 concentration; results were stronger among women of 40 years or older (5.2 mm Hg increase, 95% CI, 2.3â 8.1). Adjusted odds of borderline high and high blood pressure (categorized) were also elevated (odds ratio = 1.5, 95% CI, 1.0â 2.3). Some results included null values and are suggestive. Results suggest that reduced household air pollution, even when concentrations exceed air quality guidelines, may help lower cardiovascular disease risk, particularly among older subgroups.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146816/1/ina12507.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146816/2/ina12507_am.pd