[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
Early exposure to PM2.5 associated with increased risk of childhood autism; causality unproven
May 21, 2015
Exposure to fine particulate air pollution (PM2.5) during pregnancy through the first two years of a child’s life may be associated with an increased risk of the child developing autism spectrum disorder (ASD), a condition that affects one in 68 children, according to a University of Pittsburgh Graduate School of Public Health investigation of children in southwestern Pennsylvania.
The research is funded by The Heinz Endowments and published in the July edition of Environmental Research.
Study concludes air pollution directly affects cognition
May 19, 2015
Results of new analysis conducted by German and Swiss researchers suggests that air pollution directly affects cognition and is not mediated by lung function; put another way, the two are independent risk factors for cognitive decline. Although earlier studies showed that both air pollution and impaired lung function can cause cognitive deficits, it was up to now unclear whether air pollution diminishes cognition by reducing breathing ability first or whether air pollution represents an independent risk factor for cognitive deficit.
The researchers, who analyzed data from a study of 834 elderly German women, presented their findings at ATS 2015 in Denver.
U Toronto studies find traffic emissions spread farther than thought; 25% of cars causing 90% of pollution
April 28, 2015
A trio of recently published studies from a team of University of Toronto engineers has found that air pollution could be spreading up to three times farther than thought, contributing to varying levels of air quality across cities.
Past research on tailpipe criteria pollutants has shown poor air quality anywhere between 100 to 250 meters of major roadways. But in an open access paper published in the recent edition of the journal Atmospheric Pollution Research, U of T chemical engineer Greg Evans and his partners at Environment Canada have found that concentrations of pollutants from traffic are still double at a distance of 280 meters downwind from highway 400 north of Toronto.
CMU study finds controlled EV charging can reduce generation cost, but at greater health and environmental costs depending upon the generation mix
April 16, 2015
In a study focused on the PJM portion of the US electricity grid, researchers at Carnegie Mellon University (CMU) found that although charging electric vehicles at night (when electricity is cheap and wind power is typically more plentiful) could lower electricity costs, doing so also creates more air emissions, and that the health and environmental costs from these emissions outweigh the electricity cost savings. A paper describing the work is published in the ACS journal Environmental Science & Technology.
Results from the study also suggest that with sufficient coal plant retirement and sufficient wind power, controlled charging could result in positive net benefits instead of negative. The result of the analysis depends on the details of the region, notes CMU Professor Jeremy Michalek, corresponding author—i.e., other parts of the US and the world could be different. The question of electricity costs vs. health and environmental cost is important to ask everywhere, Michalek said.
Georgia Tech study projects potential mixed impacts of climate change policies on air quality
April 08, 2015
Results of a study by a team from Georgia Tech and their colleagues at NASA Goddard Institute for Space Studies and Northeast States for Coordinated Air Use Management show that national CO2emissions reductions strategies will play an important role in impacting air quality over the US. The results also show that CO2 emission reduction policies can have mixed positive and negative impacts on air quality. A paper on the study is published in the ACS journal Environmental Science & Technology.
In the study, the researchers assessed the impact of four potential climate mitigation policies—two climate tax scenarios (CT1 and CT2); a combined transportation and energy scenario (TE); a biomass energy (BE) scenario; plus a reference case—on air quality in the US in 2050 using a chemical transport model (CTM) to simulate air pollutant concentrations and applying recent climate downscaling and emissions modeling advancements.
New study finds asthma morbidity in children is enhanced in areas with high traffic-related air pollution near the home
April 07, 2015
Results from a new study by researchers at the University of California Irvine support a growing body of scientific literature indicating that sensitive populations, including children, certain ethnic groups and people of lower socioeconomic status, are more vulnerable to the effects of high exposures to traffic-related air pollution.
The UC Irvine study, which examined the effect of chronic exposure in asthmatic children living in homes near traffic pollution, was led by Ralph J. Delfino, MD, PhD, at the Department of Epidemiology. Asthma is a chronic inflammatory disorder of the airways; chronic inflammation is associated with airway (bronchial) hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing. The study was funded by the California Air Resources Board (ARB) and benefited from funding by the South Coast Air Quality Management District (SCAQMD).
U Toronto LCA suggests that with CNG as primary vehicle energy source, EVs best targeted at non-attainment areas
April 01, 2015
A team at the University of Toronto has examined the life cycle air emissions (climate change and human health) impact benefits and life cycle ownership costs of compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV), using a gasoline-fueled conventional vehicle as a reference.
Among their findings, published in a paper in the ACS journal Environmental Science & Technology, are that policies should for the foreseeable future focus on the niche adoption of plug-in vehicles in non-attainment regions, as CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits.
Evidence from glacier ice: Until it was banned, leaded gasoline dominated the anthropogenic lead emissions in South America
March 08, 2015
Leaded gasoline was a larger emission source of the toxic heavy metal lead than mining in South America, even though the extraction of metals from the region’s mines historically released huge quantities of lead into the environment, according to a study by researchers from the Paul Scherrer Institute PSI and the University of Bern.
The team discovered evidence of the dominance of leaded gasoline based on measurements in an ice core from Illimani glacier in Bolivia; Illimani is the highest mountain of the eastern Bolivian Andes and is located at the northeastern margin of the Andean Altiplano. The scientists found that lead from road traffic in the neighboring countries polluted the air twice as heavily as regional mining from the 1960s onwards. An open access paper on the work is published in the journal Science Advances.
HEI ACES study of lifetime animal exposure to New Technology Diesel Engine exhaust finds no lung cancer
January 27, 2015
The first study to conduct a comprehensive evaluation of lifetime exposure to new technology diesel exhaust (NTDE)—i.e., exhaust from heavy-duty diesel engines meeting EPA 2007 and later emissions requirements—has found no evidence of carcinogenic lung tumors. The Advanced Collaborative Emissions Study (ACES), released today by the Health Effects Institute (HEI), also confirmed that the concentrations of particulate matter and toxic air pollutants emitted from NTDE are more than 90% lower than emissions from traditional older diesel engines (TDE). (Earlier post.) HEI is an independent, non-profit research institute funded jointly by the US Environmental Protection Agency (EPA) and the worldwide motor vehicle industry.
The study exposed laboratory rats 80 hours a week, for up to 30 months, to emissions from a heavy-duty diesel engine meeting 2007 US EPA standards using new filters and other control technology. The study evaluated the long-term effects of multiple concentrations of inhaled NTDE in male and female rats on more than 100 different biologic endpoints, including tumor development, and compared the results with biologic effects seen in earlier studies in rats after exposure to TDE.
UBC study associates exposure to diesel exhaust with changes in DNA methylation
January 09, 2015
As an organism lives and grows, chemical reactions activate and deactivate parts of its genome at strategic times and in specific location. (Epigenetics is the study of these reactions.) DNA methylation—a chemical process in which a methyl group is added to cytosine primarily in the context of a cytosine-guanine dinucleotide (CpG)—is one of several epigenetic mechanisms that cells use to control gene expression.
While changes in DNA methylation have been associated with traffic-related air pollution in observational studies, the specific mechanisms have not been explored in a controlled study of asthmatics. In an open access study published in the journal Particle and Fibre Toxicology, a team from the University of British Columbia investigated the short-term effects of diesel exhaust inhalation on DNA methylation levels at CpG sites across the genome in circulating blood in asthmatics.
New Volvo XC90 debuts enhanced multi-filter that improves interior air quality
November 13, 2014
Volvo is introducing a larger, more efficient multi-filter in its cabins as part of its CleanZone initiative. CleanZone is an approach to controlling interior air quality and providing a better driving environment through innovative solutions for enhanced wellbeing and health. Drivers can breathe easier because most microscopic, hazardous “fine dust” particles will now be prevented from entering the car.
The multi-filter was designed especially for the SPA platform and will first appear in the all-new XC90 in the beginning of 2015. It features a larger design that intercepts more particulates and pollen, as well as a layer of active charcoal that effectively removes a range of contaminants that can impact the health of drivers.
Study: surface ozone in India in 2005 damaged 6M tonnes of crops, enough to feed 94M people in poverty
September 04, 2014
Surface ozone pollution in India damaged 6 million metric tons (6.7 million US tons) of India’s wheat, rice, soybean and cotton crops in 2005, according to a new study published in Geophysical Research Letters, a journal of the American Geophysical Union.
India could feed 94 million people with the lost wheat and rice crops, or about a third of the country’s poor, according to Sachin Ghude, an atmospheric scientist at the Indian Institute of Tropical Meteorology (IITM) in Pune, India and lead author of the new study. There are about 270 million Indians that live in poverty, according to the study.
EPA staff policy assessment recommends reduction in ozone standard from 75 ppb to 60-70 ppb
August 31, 2014
The staff of the US Environmental Protection Agency’s (EPA) Office of Air Quality Planning and Standards (OAQPS) has released the final version of the policy assessment (PA) for the review of the ozone (O3) National Ambient Air Quality Standards (NAAQS).
Among the staff recommendations are to further reduce the primary ozone standard from the current 75 ppb (parts per billion) to a revised level within the range of 70 ppb to 60 ppb—and preferably below 70 ppb.
Study finds external effects negate Hong Kong local efforts to reduce ozone pollution; multiregional policies needed
August 29, 2014
Researchers from Hong Kong Polytechnic University, Hong Kong’s Environmental Protection Department and UC Irvine present in a paper in the ACS journal Environmental Science & Technology direct evidence that increasing regional effects have negated local control efforts for O3 (ozone) pollution in Hong Kong over the past decade.
The researchers analyzed the daily maximum 8 h average O3 and Ox (=O3+NO2) concentrations observed during the high O3 season (September–November) at Air Quality Monitoring Stations. They found that the locally produced Ox showed a statistically significant decreasing trend over 2002–2013 in Hong Kong. Analysis by an observation-based model confirmed this decline in in situ Ox production, which the team attributed to a reduction in aromatic hydrocarbons.
Study: open trash burning worldwide significantly worsening air pollution; unaccounted for in emission inventories
August 28, 2014
Unregulated open trash burning around the globe is pumping far more pollution into the atmosphere than shown by official records. A new study led by the National Center for Atmospheric Research (NCAR) estimates that more than 40% of the world’s garbage is burned in such fires, emitting gases and particles that can substantially affect human health and climate change.
The new study provides the first rough estimates, on a country-by-country basis, of pollutants such as particulates, carbon monoxide, and mercury that are emitted by the fires. Such pollutants have been linked to serious medical issues. The researchers also estimated emissions of carbon dioxide, the most common greenhouse gas produced by human activity. Their paper is published in the ACS journal Environmental Science & Technology.
Black carbon linked to increased cardiovascular risk; exacerbated by co-exposure to motor vehicle emissions
August 26, 2014
Black carbon (BC) from incomplete biomass and fossil fuel combustion is the most strongly light-absorbing component of particulate matter (PM) air pollution and a major climate-forcing emission. A new international study led by McGill University (Canada) Professor Jill Baumgartner suggests that black carbon may also increase the risk of cardiovascular disease. The team’s findings are published in the Proceedings of the National Academy of Sciences of the United States (PNAS).
China’s particulate matter (PM) air pollution significantly exceeds health guidelines and is driven by industrial emissions, motor vehicles, and household use of biomass and coal fuels. Baumgartner and her colleagues measured the daily exposure to different types of air pollutants, including black carbon, in 280 women (mean age 51.9 y) in China’s rural Yunnan province, where biomass fuels are commonly used. They found that found that BC exposure from biomass smoke is more strongly associated with blood pressure—which directly impacts cardiovascular risk—than total PM mass, and that co-exposure to motor vehicle emissions may strengthen BC’s impact. Air pollution mitigation efforts focusing on reducing combustion pollution are likely to have major benefits for climate and human health.
MIT study finds air quality co-benefits of US carbon policies can significantly offset costs, depending upon the policy
August 25, 2014
The human health benefits associated with improvements in air quality related to the reduction in greenhouse gas emissions improvements can offset 26–1,050% of the cost of US carbon policies, depending upon the type of policy, according to a new study by a team from MIT. (Air quality co-benefits are additional to climate benefits realized from reduced CO2 emissions.)
In a paper published in the journal Nature Climate Science, the MIT researchers took a systems-level approach to analyzing how climate policies influence air quality, focusing on US emissions of O3 and PM2.5 precursors through 2030. They assessed the costs and air-quality-related benefits of three potential national-scale climate policies, examining the entire pathway linking climate policies, economic sector responses, emissions, regional air quality, human health and related economic impacts.
EPA report shows progress in reducing urban air toxics across US; 50% reduction from mobile sources since 1990
August 22, 2014
The US Environmental Protection Agency (EPA) released the Second Integrated Urban Air Toxics Report to Congress—the final of two reports required under the Clean Air Act (CAA) to inform Congress of progress in reducing public health risks from urban air toxics (also referred to as hazardous air pollutants or HAPs). HAPs are defined as those pollutants that cause or may cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental and ecological effects.
Using national emissions and air quality data, the Urban Air Toxics Report shows the substantial progress that has been made to reduce air toxics across the country since the Clean Air Act Amendments of 1990. Among the results highlighted is the removal of an estimated 1.5 million tons per year of HAPs from mobile sources, which represents a 50% reduction in mobile source HAP emissions. With additional fleet turnover, EPA expects these reductions to grow to 80% by the year 2030.
NIST study suggests severe corrosion in underground gasoline storage tanks may require component replacement sooner than expected; 500K USTs in US
July 30, 2014
|Optical micrographs of severe corrosion on steel alloy samples exposed to ethanol and acetic acid vapors—conditions typical of underground gasoline storage tanks—after 355 hours, 643 hours, and 932 hours. Source: NIST. Click to enlarge.|
In recent years, field inspectors in nine states have reported many rapidly corroding underground gasoline storage tank (UST) components such as sump pumps. These incidents are generally associated with use of gasoline-ethanol blends and the presence of bacteria, Acetobacter aceti, which convert ethanol to acetic acid, a component of vinegar. Corrosion can result in failures, leaks and contamination of groundwater, a source of drinking water.
Following up on the inspectors’ findings, a National Institute of Standards and Technology (NIST) laboratory study has demonstrated severe corrosion—rapidly eating through 1 millimeter of wall thickness per year—on steel alloy samples exposed to ethanol and acetic acid vapors. Based on this finding, NIST researchers suggest gasoline stations may need to replace submersible pump casings, typically made of steel or cast iron, sooner than expected.
Non-intrusive bio-monitoring system anticipates driver fatigue in the vehicle to prevent accidents
July 23, 2014
The Instituto de Biomecánica de Valencia (Biomechanics Institute - IBV) and its consortium partners in the European project HARKEN have developed a non-intrusive system integrated into smart materials which is capable of monitoring cardiac and respiratory rhythms in order to prevent drivers from falling asleep. The two-year project had its final meeting in June.
The system is based on three main components: the seat sensor, the seat belt sensor and the signal-processing unit (SPU), which processes the sensor data in real time. All are invisible to the user.
Critical review finds actual measurement data on segments of natural gas lifecycle sparse or lacking
July 08, 2014
After a critical review of the literature on the air impacts of increased natural gas acquisition, processing, and use, a team of US researchers has determined that that actual measurement data on various individual segments of the natural gas life cycle are sparse or critically lacking.
National and state regulators primarily use generic emission inventories to assess the climate, air quality, and health impacts of natural gas systems. These inventories rely on limited, incomplete, and sometimes outdated emission factors and activity data, based on few measurements, they found. In their paper, published in the ACS journal Environmental Science & Technology, they make a number of recommendations to maximize the benefits and minimize the negative impacts of the natural gas resource.
Pilot at BMW Munich plant evaluating use in vehicle assembly of custom orthotic devices produced by 3D printing
July 02, 2014
A pilot project in BMW’s Munich vehicle assembly plan is exploring the benefits of a new and innovative ergonomic tool—a flexible finger cot, which protects workers against excess strains on the thumb joints while carrying out certain assembly activities. The project is part of a dissertation in cooperation with the Department of Ergonomics at the Technical University of Munich.
Each of the flexible assembly aids is a unique piece, customized to the match the form and size of a worker’s hand. The BMW Group makes these orthotic devices in-house, using additive production procedures—i.e., “3D printing”.
China iCET releases 2014 Green Car China report ranking mainstream cars by green and health impacts
July 01, 2014
|Only hybrids performed very well on both the green rating and the smog index. Source: iCET. Click to enlarge.|
China’s Innovation Center for Energy and Transportation (iCET) recently released its 2014 Green Car China Annual Report, an evaluation of mainstream vehicles on sale in China by their lifecycle impacts and their health impacts.
Based on the lifecycle impact assessment, every vehicle obtains a green score (0-10). The higher the green score, the lower the environmental impact (i.e., the greener it is). After normalizing the health impacts of tailpipe emissions, every vehicle also obtains a smog index score (1-8). The lower the smog score, the more eco-friendly it is.
Researchers review risk to water resources from unconventional shale gas development in US
June 19, 2014
A team from Duke University, Stanford University, Dartmouth College and Ohio State University has published in the ACS journal Environmental Science & Technology an overview and synopsis of recent investigations (as of January 2014) into one set of possible environmental impacts from unconventional shale gas development: the potential risks to water resources.
They identified four potential modes of water resource degradation: (1) shallow aquifers contaminated by fugitive natural gas (i.e., stray gas contamination) from leaking shale gas and conventional oil and gas wells, potentially followed by water contamination from hydraulic fracturing fluids and/or formation waters from the deep formations; (2) surface water contamination from spills, leaks, and the disposal of inadequately treated wastewater or hydraulic fracturing fluids; (3) accumulation of toxic and radioactive elements in soil and the sediments of rivers and lakes exposed to wastewater or fluids used in hydraulic fracturing; and (4) the overuse of water resources, which can compete with other water uses such as agriculture in water-limited environments.
Study estimates global black carbon emissions up 72% from 1960-2007; BC emissions intensity down 52%
May 31, 2014
|Black carbon emissions and BC emissions intensity per year. Credit: ACS, Wang et al. Click to enlarge.|
A study led by a team from Peking University has estimated that global black carbon (BC) emissions increased from 5.3 teragrams/year in 1960 to 9.1 teragrams per year in 2007 (+72%). These estimates are 11-16% higher than produced by in previous inventories, the researchers noted in a paper published in the ACS journal Environmental Science & Technology.
Over the same period, BC emission intensity—the amount of BC emitted per unit of energy production—decreased by 52% for all the regions under assessment, especially China and India.
Study shows two-stroke scooters dominant source of air pollution in many cities; asymmetric polluters
May 23, 2014
A study by European researchers has found that two-stroke (2S) scooters, although constituting a small fraction of the fleet, can dominate urban vehicular pollution through organic aerosol and aromatic emission factors up to thousands of times higher than from other vehicle classes. The study by the team led by researchers from the Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Switzerland, appears in the journal Nature Communications.
The team calls 2S scooters “asymmetric polluters” as their emission factors (EFs) and evidence from air quality measurements before and after bans on scooters in Asian cities suggest they may dominate vehicular pollution despite their relatively small numbers.
OECD: rising air pollution-related deaths taking heavy toll on society; more should be done to reduce transport emissions
|Deaths from outdoor air pollution by region in 2005 and 2010. From 2005 to 2010, the death rate rose by 4% worldwide, by 5% in China and by 12% in India. OECD. Click to enlarge.|
Outdoor air pollution kills some 3.5 million people across the world every year, and causes health problems from asthma to heart disease for many more, according to data collected by the World Health Organization (WHO). (Earlier post.) This pollution is costing advanced economies plus China and India an estimated US$3.5 trillion a year in premature deaths and ill health; these costs will rise without government action to limit vehicle emissions, according to a new report published by the Organisation for Economic Co-operation and Development (OECD): “The Cost of Air Pollution: Health Impacts of Road Transport”.
In OECD countries, around half the cost is from road transport, according to the report, with diesel vehicles producing the most harmful emissions. Traffic exhaust is a growing threat in fast-expanding cities in China and India, as the steady increase in the number of cars and trucks on the road undermines efforts to curb vehicle emissions.