Life cycle air quality impacts of conventional and alternative light-duty transportation in the United States (6 page pdf, Christopher W. Tessuma, Jason D. Hillb,1, and Julian D. Marshall, Proceedings of National Academy of Sciences(PNAS), Dec. 30, 2014)
Also discusses here: Electric Vehicle Batteries: Clean and Green, or Something Less?(Al Bredenberg, Contributing Writer, Design News, Sep. 7, 2015)
Today we review research into the life cycle costs in terms of GHG emissions and ptrematurte deaths resulting from the use of electric vehicles (EV) compared to conventional vahicles using gas which is a factor not only of the tailpipe emissions on the road but also on the source of the electricity used to charge the batteries and what emissions come from them. Results indicate that EVs using electricity generated from coal (which is true for southeastern USA) produce more than three times the mortalities than from conventional vehicles burning gas – and over 90% of this comes from the battery production. On the other hand, EVs using electricity from wind/solar/water have almost insignificant damages compared to gasoline powered vehicles. EVs using electricity form biofuels such as corn ethanol have impacts about 50% higher than ordinary gasoline powered vehicles. All of this underlines the importance of considering the pollution costs of the manufacture of the Lithium batteries that power many EVs, in addition to the fuel economy on the road.
Key Quotes:
“powering vehicles with corn ethanol or with coal-based or “grid average” electricity increases monetized environmental health impacts by 80% or more relative to using conventional gasoline. Conversely, EVs powered by lower emitting electricity from natural gas, wind, water, or solar power reduce environmental health impacts by 50% or more.”
“production of copper and other raw materials for batteries occurs far from people…copper ore smelting, which causes the majority of battery production SO2 emissions, mainly occurs in the sparsely populated southwestern United States.”
“In 2011, the Chinese government began shutting down graphite mines for environmental and resource protection. Stricter controls were imposed to prevent a pollution problem called “graphite rain.” USGS explains that “dust emissions from the mining of crystalline flake graphite had become a major issue, and although graphite is inert and not harmful, the air pollution from dust had become a problem to local residents and farmers.”
“Excluding battery production, impacts from wind, water, and solar (WWS) EVs .. are notably lower than from the other scenarios because WWS electrical generators do not produce emissions while in use. Emissions from battery production for the EV scenarios are tracked separately. The main emission sources for EV battery production .. are coal mining inWyoming and the Appalachian Mountains and the extraction and refinement of raw material inputs, including copper”
“Air pollution-related human health impacts for each scenario (PM2.5 and O3-related mortalities, and the corresponding monetized damages) ..range from 230 mortalities per year ($0.14 per gallon gasoline-equivalent) for the WWS EV scenario to 3,200 mortalities per year ($1.94 per gallon gasoline-equivalent) for the coal EV scenario. Estimated mortality impacts from PM2.5 are approximately an order of magnitude greater than those from O3”
“Previous studies ..have argued that to meet stated goals for GHG emission reductions, it is necessary to both electrify vehicles and decarbonize electricity generation, for example through WWS electric generation. Our results suggest that such a strategy would have the strong cobenefit of substantially reducing air quality-related mortalities (by ∼70%).”
Thursday, October 29, 2015
Tuesday, October 27, 2015
What is the Cost of Inaction on Climate Change?
Climate Change in the U.S. - Benefits of Global Action (96 page pdf, Environmental Protection Agency, Sep. 7, 2015)
Also discussed here: Can we put a value on the benefits of climate action? (Mark Dwortzan, World Economic Forum, Sep 7 2015)
Today we review an assessment of the benefits of taking action on climate change and the costs of inaction on cutting carbon emissions to limit climate warming to less than 2 C that would be realized by the end of the century in the Unites States. Impacts are many and widespread and vary in nature and cost across the various regions of the USA. Mitigation would prevent 57,000 premature deaths by 2100 with an economic benefit of $930 B. In the Great Lakes region, 520 bridges are vulnerable compared to 53 with mitigation. In the Southwest, the number of droughts and heat waves is expected to quadruple by2100 while under mitigation no increase is seen. In the Rocky Mountains, nearly 2 million more acres of forests will burn by 2100 compared to 1.5 million less with mitigation, compared to today.
Key Quotes:
“We have much more experience defining the cost of mitigation than the benefits. The goal of this project was to put a dollar value on damages from climate change in a number of sectors.”
“with no policy implemented between now and 2100, increases in global temperature will range from 3.5 to 8 degrees C, precipitation from 0.3 to 0.6 millimeters per day and sea level from 40 to 80 centimeters. Ocean acidity will also rise, threatening marine life and commercial fisheries.”
“2 C stabilization would save thousands of lives threatened by extreme heat and billions of dollars in infrastructure expenses, while preventing destruction of natural resources and ecosystems.”
“In more than 35 studies, the EPA-funded researchers pinpointed a large number of climate impacts that could be averted, or at least reduced, by a 2 C stabilization, from lost wages due to extreme temperatures, to damage to bridges from heavy river flows.”
“Unmitigated climate change is projected to exacerbate fine particulate matter pollution, especially in the Midwest and East. The annual U.S.-average PM2.5 concentrations are projected to increase by 0.3 μg m-3 (± 0.1) in 2050 and 0.7 μg m-3 (± 0.1) in 2100 in the Reference scenario.”
“the Mitigation scenario is estimated to prevent an estimated 13,000 premature deaths in 2050 (95% confidence interval of 4,800-22,000) and 57,000 premature deaths in 2100 (95% confidence interval of 21,000-95,000) compared to the Reference. Economic benefits to the U.S. of these avoided deaths are estimated at $160 billion and $930 billion in 2050 and 2100, respectively.”
“In the Great Lakes region, approximately 520 bridges are projected to be vulnerable in 2100 under the Reference scenario, compared to 65 in the Mitigation scenario.”
“In 2100, the Great Plains region is projected to incur road damages of approximately $3.5 billion in the Reference scenario, compared to $1.1 billion in the Mitigation scenario.”
“In the Southwest, the number of severe and extreme droughts is projected to nearly quadruple by the end of the century in the Reference scenario compared to today. In the Mitigation scenario, the incidence of drought is not projected to change substantially from present day.”
“In the Rocky Mountains, an estimated 1.9 million more acres are projected to burn in 2100 under the Reference scenario compared to today. In the Mitigation scenario, an estimated 1.5 million fewer acres are projected to burn compared to today.”
Also discussed here: Can we put a value on the benefits of climate action? (Mark Dwortzan, World Economic Forum, Sep 7 2015)
Today we review an assessment of the benefits of taking action on climate change and the costs of inaction on cutting carbon emissions to limit climate warming to less than 2 C that would be realized by the end of the century in the Unites States. Impacts are many and widespread and vary in nature and cost across the various regions of the USA. Mitigation would prevent 57,000 premature deaths by 2100 with an economic benefit of $930 B. In the Great Lakes region, 520 bridges are vulnerable compared to 53 with mitigation. In the Southwest, the number of droughts and heat waves is expected to quadruple by2100 while under mitigation no increase is seen. In the Rocky Mountains, nearly 2 million more acres of forests will burn by 2100 compared to 1.5 million less with mitigation, compared to today.
Key Quotes:
“We have much more experience defining the cost of mitigation than the benefits. The goal of this project was to put a dollar value on damages from climate change in a number of sectors.”
“with no policy implemented between now and 2100, increases in global temperature will range from 3.5 to 8 degrees C, precipitation from 0.3 to 0.6 millimeters per day and sea level from 40 to 80 centimeters. Ocean acidity will also rise, threatening marine life and commercial fisheries.”
“2 C stabilization would save thousands of lives threatened by extreme heat and billions of dollars in infrastructure expenses, while preventing destruction of natural resources and ecosystems.”
“In more than 35 studies, the EPA-funded researchers pinpointed a large number of climate impacts that could be averted, or at least reduced, by a 2 C stabilization, from lost wages due to extreme temperatures, to damage to bridges from heavy river flows.”
“Unmitigated climate change is projected to exacerbate fine particulate matter pollution, especially in the Midwest and East. The annual U.S.-average PM2.5 concentrations are projected to increase by 0.3 μg m-3 (± 0.1) in 2050 and 0.7 μg m-3 (± 0.1) in 2100 in the Reference scenario.”
“the Mitigation scenario is estimated to prevent an estimated 13,000 premature deaths in 2050 (95% confidence interval of 4,800-22,000) and 57,000 premature deaths in 2100 (95% confidence interval of 21,000-95,000) compared to the Reference. Economic benefits to the U.S. of these avoided deaths are estimated at $160 billion and $930 billion in 2050 and 2100, respectively.”
“In the Great Lakes region, approximately 520 bridges are projected to be vulnerable in 2100 under the Reference scenario, compared to 65 in the Mitigation scenario.”
“In 2100, the Great Plains region is projected to incur road damages of approximately $3.5 billion in the Reference scenario, compared to $1.1 billion in the Mitigation scenario.”
“In the Southwest, the number of severe and extreme droughts is projected to nearly quadruple by the end of the century in the Reference scenario compared to today. In the Mitigation scenario, the incidence of drought is not projected to change substantially from present day.”
“In the Rocky Mountains, an estimated 1.9 million more acres are projected to burn in 2100 under the Reference scenario compared to today. In the Mitigation scenario, an estimated 1.5 million fewer acres are projected to burn compared to today.”
Thursday, October 22, 2015
The Impact of Particulate Air Pollution on Liver Diseases
 |
| Age-standardised disability-adjusted life year (DALY) rates from Cirrhosis of the liver by country (per 100,000 inhabitants). (Photo credit: Wikipedia) |
Exposure to Fine Airborne Particulate Matters Induces Hepatic Fibrosis in Murine Models (Abstract, Ze Zheng, Xuebao Zhang, Jiemei Wang, Aditya Dandeka, Hyunbae Kim, Yining Qiu, Xiaohua Xu, Yuqi Cui, Aixia Wang, Lung Chi Chen, Sanjay Rajagopalan, Qinghua Sun, Kezhong Zhang, Journal of Hepatology, Jul. 25, 2015)
Also discussed here: Scientists discover mechanism for air pollution-induced liver disease (Science Daily, Sep. 2, 2015)
Today we review research into the effects that particulate matter has on the liver. Results indicate a causal link between PM 2.5 and liver fibrosis which is associated with liver cancer and most types of chronic liver diseases. Those who have a high exposure to particulates from daily traffic need to have their markers for liver disease checked more closely.
Key Quotes:
“exposure to air pollution has a direct adverse health effect on the liver and causes liver fibrosis, an illness associated with metabolic disease and liver cancer”
“PM2.5 has direct effects on the liver, triggering liver fibrosis, a pathological condition characterized by accumulation of the extracellular matrix protein collagen that occurs in most types of chronic liver diseases.”
“Utilizing molecular, cellular and pathological approaches, the team discovered the stress sensor on the cell membrane that initiates PM2.5-triggered stress signals and the mediators inside the cell that transduces the signaling”
"Liver fibrosis is an advanced stage of chronic liver injuries caused by chronic hepatitis viral infection, obesity, alcoholism or autoimmune diseases. Our work defined that air pollution, specifically PM2.5 pollutant, is an independent risk factor of liver fibrosis.”
"Physicians or health care professionals should monitor liver pathology and consider preventive therapeutic strategies for liver disease for populations and patients in urban air pollution environments."
Tuesday, October 20, 2015
How do Stranded Assets Interfere with Carbon Taxes to Achieve a Low Carbon Economy?
Assessing carbon lock-in (8 page pdf, Peter Erickson, Sivan Kartha, Michael Lazarus and Kevin Tempest, Environ. Res. Lett., Aug. 25, 2015)
Today we review the results of economic modeling which examined how high carbon emitters and their infrastructure and supporting networks tend to discourage attempts to transform society to a low carbon economy in time to avoid exceeding the 450 ppm/2 deg C warming that is the global target. Results show that coal fired power plants are the biggest obstacle world-wide and their lifetimes lasting decades also discourage early conversion to low catrbon. The model also predicts what level of carbon price would make continued investment in these old technologies uneconomic. Coal power plants require a carbon tax above $30 US/tonne. Other stranded assets include gas power plants and combustion engine cars and their economic carbon tax trigger point is higher than for coal.
Key Quotes:
“‘carbon lock-in refers to the dynamic whereby prior decisions relating to GHG-emitting technologies, infrastructure, practices, and their supporting networks constrain future paths, making it more challenging, even impossible, to subsequently pursue more optimal paths toward low-carbon objectives”
“at the global level…carbon lock-in is greatest, globally, for coal power plants, gas power plants, and oil-based vehicles.”
“continued near-term (through 2020) investment in conventional technologies instead of low-carbon alternatives would increase investment costs four-fold in the longer term (through 2035)”
“The approach can be readily applied at the national or regional scale and may be of particular relevance to policymakers interested in enhancing flexibility for deeper emissions cuts in the future, and therefore in limiting the future costs associated with ‘stranded assets’ “
“conventional technologies might be retired early or ‘unlocked’ in the future, especially if the full costs of an alternative, low-carbon technology were to fall below the marginal (in this case, the ongoing operating) costs of the conventional technology, accounting for all climate policies”
“This analysis indicates that, globally, coal-fired power plants are long-lived (averaging 45 years), and large numbers are expected over the next 15 years (over-committing 200 GtCO2), creating further political and institutional entrenchment. Unlocking coal plants would, on average, require a carbon price of about USD 30 per tonne, lower than for most technologies, but still higher than carbon prices in most countries”
“in addition to pursuing policies to reduce energy demand and install low-carbon power generation, policymakers could also then begin limiting investments in technologies, such as those identified here, that pose the greatest risks of carbon lock-in.”
Today we review the results of economic modeling which examined how high carbon emitters and their infrastructure and supporting networks tend to discourage attempts to transform society to a low carbon economy in time to avoid exceeding the 450 ppm/2 deg C warming that is the global target. Results show that coal fired power plants are the biggest obstacle world-wide and their lifetimes lasting decades also discourage early conversion to low catrbon. The model also predicts what level of carbon price would make continued investment in these old technologies uneconomic. Coal power plants require a carbon tax above $30 US/tonne. Other stranded assets include gas power plants and combustion engine cars and their economic carbon tax trigger point is higher than for coal.
Key Quotes:
“‘carbon lock-in refers to the dynamic whereby prior decisions relating to GHG-emitting technologies, infrastructure, practices, and their supporting networks constrain future paths, making it more challenging, even impossible, to subsequently pursue more optimal paths toward low-carbon objectives”
“at the global level…carbon lock-in is greatest, globally, for coal power plants, gas power plants, and oil-based vehicles.”
“continued near-term (through 2020) investment in conventional technologies instead of low-carbon alternatives would increase investment costs four-fold in the longer term (through 2035)”
“The approach can be readily applied at the national or regional scale and may be of particular relevance to policymakers interested in enhancing flexibility for deeper emissions cuts in the future, and therefore in limiting the future costs associated with ‘stranded assets’ “
“conventional technologies might be retired early or ‘unlocked’ in the future, especially if the full costs of an alternative, low-carbon technology were to fall below the marginal (in this case, the ongoing operating) costs of the conventional technology, accounting for all climate policies”
“This analysis indicates that, globally, coal-fired power plants are long-lived (averaging 45 years), and large numbers are expected over the next 15 years (over-committing 200 GtCO2), creating further political and institutional entrenchment. Unlocking coal plants would, on average, require a carbon price of about USD 30 per tonne, lower than for most technologies, but still higher than carbon prices in most countries”
“in addition to pursuing policies to reduce energy demand and install low-carbon power generation, policymakers could also then begin limiting investments in technologies, such as those identified here, that pose the greatest risks of carbon lock-in.”
Thursday, October 15, 2015
Where Do You Find the Most Cancer-Causing Air Pollutants in Canada?
Identifying potential exposure reduction priorities using regional rankings based on emissions of known and suspected carcinogens to outdoor air in Canada (16 page pdf, Eleanor M. Setton, Basil Veerman, Anders Erickson, Steeve Deschenes, Roz Cheasley, Karla Poplawski, Paul A. Demers and C. Peter Keller, Environmental Health, Aug. 22, 2015)
Today we review a description of a new national inventory of hazardous air pollutants that are rated according to the exposure of the population to various carcinogens present. Results indicate that of 21 pollutants, arsenic and benzene are found at the top of the list for each province with most (73%) of the emissions coming from agriculture, construction and transportation 15% from residential wood burning and forest fires and only 6% from industrial sources. Quebec was found to have the highest contributions from arsenic.
Key Quotes:
“long-term health risks (cancer and non-cancer) were estimated by calculating exposure (intake) and applying cancer risk factors or non-cancer hazard quotients to the resulting intake level. This process enables the ranking of air pollutants based on lifetime excess cancer risk or non-cancer hazard indices in each census tract[under the National-Scale Air Toxics Assessment (NATA) program ]”
“the CAREX Emissions Mapping Project (EMP) in Canada, a Google Earth-based data set that includes indicators based on emissions of 21 known and suspected carcinogens to air, as reported to the NPRI [National Pollutant Release Inventory (NPRI)] and from our own estimates of emissions from transportation and residential heating”
"in 2011, Environment Canada estimated emissions of fine particulates in Canada to be on the order of 1.18 million tonnes …Of that, 73 % was attributed to dust from agriculture, construction, and transportation; 9 % to residential wood burning; 6 % to forest fires; and only 6 % to industrial activities”
“between 94 and 99 % of Total TEQ [annual toxic equivalent emissions to air in kilograms for each substance], for each province or territory is contributed by only five substances, based on the associated TEQ ranks ... Arsenic was most frequently the top contributor to Total TEQ, followed by benzene, benzo[a]pyrene, 2, 3, 7, 8-tetrachlorodibenzo -p-dioxin (TCDD), 1,3-butadiene, lead and benzo[b]fluoranthene”
“in Quebec, arsenic emissions are the top contributor to Total TEQ”
“our results suggest that wood smoke from residential heating may be an important source of cancer-related pollutants, indicating a shift away from focusing on industrial activities may be warranted in some regions of Canada.”
Today we review a description of a new national inventory of hazardous air pollutants that are rated according to the exposure of the population to various carcinogens present. Results indicate that of 21 pollutants, arsenic and benzene are found at the top of the list for each province with most (73%) of the emissions coming from agriculture, construction and transportation 15% from residential wood burning and forest fires and only 6% from industrial sources. Quebec was found to have the highest contributions from arsenic.
Key Quotes:
“long-term health risks (cancer and non-cancer) were estimated by calculating exposure (intake) and applying cancer risk factors or non-cancer hazard quotients to the resulting intake level. This process enables the ranking of air pollutants based on lifetime excess cancer risk or non-cancer hazard indices in each census tract[under the National-Scale Air Toxics Assessment (NATA) program ]”
“the CAREX Emissions Mapping Project (EMP) in Canada, a Google Earth-based data set that includes indicators based on emissions of 21 known and suspected carcinogens to air, as reported to the NPRI [National Pollutant Release Inventory (NPRI)] and from our own estimates of emissions from transportation and residential heating”
"in 2011, Environment Canada estimated emissions of fine particulates in Canada to be on the order of 1.18 million tonnes …Of that, 73 % was attributed to dust from agriculture, construction, and transportation; 9 % to residential wood burning; 6 % to forest fires; and only 6 % to industrial activities”
“between 94 and 99 % of Total TEQ [annual toxic equivalent emissions to air in kilograms for each substance], for each province or territory is contributed by only five substances, based on the associated TEQ ranks ... Arsenic was most frequently the top contributor to Total TEQ, followed by benzene, benzo[a]pyrene, 2, 3, 7, 8-tetrachlorodibenzo -p-dioxin (TCDD), 1,3-butadiene, lead and benzo[b]fluoranthene”
“in Quebec, arsenic emissions are the top contributor to Total TEQ”
“our results suggest that wood smoke from residential heating may be an important source of cancer-related pollutants, indicating a shift away from focusing on industrial activities may be warranted in some regions of Canada.”
Tuesday, October 13, 2015
How do Impacts of Traffic-Related Air Pollution on Health Change?
 |
| English: Main complications of persistent high blood pressure. Sources are found in main article: Wikipedia:Hypertension#Complications. To discuss image, please see Template_talk:Häggström diagrams. To edit, please use the svg version, convert to png and update both versions online. (Photo credit: Wikipedia) |
Repeated measures of inflammation, blood pressure, and heart rate variability associated with traffic exposures in healthy adults (12 page pdf, Jaime E. Mirowsky, Richard E. Peltier, Morton Lippmann, George Thurston, Lung-Chi Chen, Lucas Neas, David Diaz-Sanchez, Robert Laumbach, Jacqueline D. Carter and Terry Gordon. Environmental Health, Aug. 15, 2015)
Key Quotes:
“the present study extends the previous literature of measuring short-term adverse health effects associated with microenvironmental exposures to traffic-related air pollutants”
“In the healthy participants in this study, acute exposures to traffic pollutants elicited cardiovascular and inflammatory changes that were most strongly associated with PM 2.5 EC [Elemental carbon] and OC[Organic carbon]”
“the current study supports results in the literature regarding traffic-related pollutants and their impact on HRV [Heart rate variability] endpoints, but the BP [Blood pressure] measurements found in this study are in contrast to previously published work.”
“we have shown that in our study population of 23 subjects, acute physiological and biological changes can occur in a healthy population following a 2 h walking exposure to near-walkway traffic”
“Associations were found between increases in markers of inflammation in the blood and decreases in heart rate variability with increasing concentrations of EC. Overall, acute changes in cardiovascular measurements and markers of inflammation in the blood were observed in healthy adults exposed to traffic-related pollution.”
Thursday, October 8, 2015
The "Weather Penalty":How Does It Affect the Health Impact of Air Pollution?
The impact of weather changes on air quality and health in the United States in 1994–2012 (12 page pdf, Iny Jhun, BrentACoull, Joel Schwartz, Bryan Hubbell and Petros Koutrakis, Environ. Res. Lett., Aug. 12, 2015)
Today we review research in to the ways that various weather parameters affects air quality and what this means in terms of additional deaths, as analyzed over a period of eight years in the USA. Windspeed and temperature were considered the most important. Results indicate that often a given parameter has opposite effects on the degree of air pollution- for example, warmer temperatures can both increase and reduce the production of ozone. The annual average weather penalty was estimated as 290 deaths due to O3 and 770 deaths related to PM.
Key Quotes:
“O3 primarily results from reactions between nitrogen oxides and volatile organic compounds in the presence of sunlight, and high temperature, low humidity, and low wind speed conditions favor O3 formation”
“Weather impacts onPM2.5 can be more variable, given the diversity of particle components (e.g., sulfate, nitrate, organic carbon, and elemental carbon). In general, particles are efficiently scavenged through wet deposition”
“Water vapor has competing effects onO3 concentrations by facilitating hydroxyl radical production from O3 photolysis, which can collectively yield a net O3 loss (via photolysis) or netO3 production (via hydroxyl radical chemistry).”
“Decreases in wind speed were consistently associated withO3 increases in the warm season. Low wind speed and high ambient temperature are conditions characteristic of stagnation leading to favorable conditions for O3 formation during the summertime”
“In summary, much of the weather penalty on O3 can be attributed to changes in temperature and water vapor pressure, but the significant decline in windspeeds also contributed to the warm season O3 penalty.”
“Temperature and wind speed were the most important determinants of PM2.5 concentrations and trends in most regions…Temperature increases can have opposing effects on PM2.5 by increasing sulfate concentrations through increased oxidation and decreasing nitrate levels due to ammonium nitrate volatilization”
“weather-related penalty on air quality had the greatest mortality impacts in the Eastern US (NE, SE, and IM), where both population size and weather penalties were highest.. The weather penalty was associated with 290 annual deaths related to O3 and 770 annual deaths related to PM2.5.”
Today we review research in to the ways that various weather parameters affects air quality and what this means in terms of additional deaths, as analyzed over a period of eight years in the USA. Windspeed and temperature were considered the most important. Results indicate that often a given parameter has opposite effects on the degree of air pollution- for example, warmer temperatures can both increase and reduce the production of ozone. The annual average weather penalty was estimated as 290 deaths due to O3 and 770 deaths related to PM.
Key Quotes:
“O3 primarily results from reactions between nitrogen oxides and volatile organic compounds in the presence of sunlight, and high temperature, low humidity, and low wind speed conditions favor O3 formation”
“Weather impacts onPM2.5 can be more variable, given the diversity of particle components (e.g., sulfate, nitrate, organic carbon, and elemental carbon). In general, particles are efficiently scavenged through wet deposition”
“Water vapor has competing effects onO3 concentrations by facilitating hydroxyl radical production from O3 photolysis, which can collectively yield a net O3 loss (via photolysis) or netO3 production (via hydroxyl radical chemistry).”
“Decreases in wind speed were consistently associated withO3 increases in the warm season. Low wind speed and high ambient temperature are conditions characteristic of stagnation leading to favorable conditions for O3 formation during the summertime”
“In summary, much of the weather penalty on O3 can be attributed to changes in temperature and water vapor pressure, but the significant decline in windspeeds also contributed to the warm season O3 penalty.”
“Temperature and wind speed were the most important determinants of PM2.5 concentrations and trends in most regions…Temperature increases can have opposing effects on PM2.5 by increasing sulfate concentrations through increased oxidation and decreasing nitrate levels due to ammonium nitrate volatilization”
“weather-related penalty on air quality had the greatest mortality impacts in the Eastern US (NE, SE, and IM), where both population size and weather penalties were highest.. The weather penalty was associated with 290 annual deaths related to O3 and 770 annual deaths related to PM2.5.”
Subscribe to:
Posts (Atom)