particulate matter

Study: Declines in air pollutants had direct positive effect on children’s health

kkrisberg — Tue, 17 Mar 2015 17:56:40 +0000

Study: Declines in air pollutants had direct positive effect on children’s health

In the first study of its kind, researchers have found that improved air quality in southern California had a direct effect on children’s respiratory health. The findings point to the effectiveness of smart public health policy — in other words, even as southern California experienced increases in traffic and commerce, aggressive air pollution policies resulted in cleaner air and healthier kids.

Published earlier this month in the New England Journal of Medicine, the study concluded that air quality improvements in the southern California communities studied were associated with significantly positive effects on lung function growth in children. In even simpler terms, as pollution declined, children’s lungs actually grew stronger.

“The most surprising part was the magnitude of improvements over a relatively short period of time,” study co-author W. James Gauderman, professor of preventive medicine at the University of Southern California (USC) Keck School of Medicine, told me. “It’s really an amazing turnaround to have had these improvements even with increased sources of emissions.”

To conduct the study, researchers measured annual lung function among more than 2,100 children in three different cohorts and during three separate time periods: 1994-1998, 1997-2001 and 2007-2011. The children, who were 11 years old at the beginning of each time period and 15 years old at the end, hailed from the communities of Long Beach, Mira Loma, Riverside, San Dimas and Upland. Lung function growth over the four-year intervals was measured via forced expiratory volume in one second (also known as FEV and defined as the amount of air exhaled in the first second of a forced exhalation) and forced vital capacity (known as FVC and defined as the amount of air exhaled after taking the deepest breath possible). Pollutant levels were gleaned from data collected via outdoor monitoring stations.

Researchers found that lung growth between ages 11 and 15 was more than 10 percent greater for the children exposed to lower levels of nitrogen dioxide from 2007 to 2011 compared to children breathing higher levels of the air pollutant from 1994 to 1998. Also, the percentage of 15-year-old children with abnormally low lung function dropped from about 8 percent within the 1994-1998 study cohort to 6.3 percent in the 1997-2001 cohort to 3.6 percent in the 2007-2011 cohort. Those improvements coincided with the enactment of health-driven air quality policies and vehicle emissions standards, which have produced dramatic air quality results. The study found that combined exposure to two pollutants harmful to human health — nitrogen dioxide and particulate matter less than 2.5 microns (PM2.5) — declined by about 40 percent for the 2007-2011 cohort when compared to the 1994-1998 cohort.

What’s even more impressive is that the positive gains in children’s lung function were documented even after researchers adjusted for confounding variables, such as tobacco smoke exposure, health insurance status, parental educational attainment, asthma and indoor pollutants, such as pets and mold. Indeed, both children with and without asthma experienced better lung function growth as air quality improved. Study authors Gauderman, Robert Urman, Edward Avol, Kiros Berhane, Rob McConnell, Edward Rappaport, Roger Chang, Fred Lurmann and Frank Gilliland wrote:

This study shows an association between secular improvements in air quality in southern California and measurable improvements in lung-function development in children. Improved lung function was most strongly associated with lower levels of particulate pollution (PM2.5 and PM10) and nitrogen dioxide. These associations were observed in boys and girls, Hispanic white and non-Hispanic white children, and children with asthma and children without asthma, which suggests that all children have the potential to benefit from improvements in air quality.

Gauderman told me that while we’ve known for some time that breathing dirty air is bad for kids via studies that compare polluted and unpolluted communities, this is the first study to start with a polluted community and follows its young residents over time as air pollutants decline. He noted that the study caught kids at a time of rapid lung development. By age 15, lung function development in girls is about finished and boys’ development is slowing down, Gauderman said, and so by the time adolescents transition into adulthood, they have the lungs they’ll have for life. That’s why it’s so important to encourage respiratory health in the early years, as reduced lung capacity and function is a primary risk factor for lung disease in adulthood as well as reduced lifespan. In other words, kids who grow up breathing cleaner air may have a jumpstart on becoming healthier adults, he said.

Gauderman added that among the pollutants studied, declines in nitrogen dioxide and particulate matter, which are products of fuel combustion, were most associated with improvements in kids’ health. And because such pollutants are common in urban areas, Gauderman said similar health improvements could be expected in other communities that pursue stricter clean air policies.

“In an urban environment, you obviously can’t make decisions about breathing the air or not, so it really does take societal decisions to change those exposures,” Gauderman told me. “Given the projections we have for even more cars, more people and more economic activity, we definitely do not want to lose the gains we’ve made. It’s going to take continued vigilance — we certainly don’t want to get complacent as if the job is done.”

Marlon Boarnet, professor and senior associate dean for academic affairs as well as director of graduate programs in urban planning and development at the USC Sol Price School of Public Policy, told me that the children’s lung study is a reminder that air quality protections and a robust economy can coexist. But he added that a strong regulatory regime, political support and decades-long commitment were “absolutely necessary” to achieving the clean air and health gains documented in the study.

“This was absolutely a result of public policy, there’s no question about it — end of story,” he said. “This would not have happened without policy. …If you want to have reduced lung capacity in our children, then by all means, leave it to the market.”

To read a full copy of the children's lung study, visit the New England Journal of Medicine.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.

kkrisberg Tue, 03/17/2015 - 13:56

Diesel exhaust a human carcinogen concludes WHO's cancer panel

cmonforton — Tue, 12 Jun 2012 12:52:27 +0000

Diesel exhaust a human carcinogen concludes WHO's cancer panel

A panel of scientific experts convened by the World Health Organization's (WHO) International Agency for Research on Cancer (IARC) concluded today that diesel engine exhaust is carcinogenic to humans. Previously, the IARC classification for diesel exhaust was "probably carcinogenic to humans," but with the publication of additional epidemiological and toxicological studies over the last 20 years, the expert panel determined there was sufficient evidence to change the compound's cancer designation. The IARC panel wrote:

"The scientific evidence was reviewed thoroughly by the Working Group and overall it was concluded that there was sufficient evidence in humans for the carcinogenicity of diesel exhaust. The Working Group found that diesel exhaust is a cause of lung cancer (sufficient evidence) and also noted a positive association (limited evidence) with an increased risk of bladder cancer."

Just prior to IARC's announcement, the Diesel Technology Forum (DTF) issued a statement about clean-diesel technology. The trade group suggests in its statement that the U.S. EPA and the California Air Resources Board say that diesel exhaust has few biological effects. One reporter, who participated in the IARC's news conference, quoted from the DTF's statement which relates to the Advanced Collaborative Emissions Study (ACES). That statement reads:

"This landmark study sponsored by U.S. Environmental Protection Agency, California Air Resources Board, industry and HEI suggest 'few biologic effects to diesel exhaust exposure.'"

The IARC officials were unable to comment on the statement given its vague nature, but responded by saying that the expert panel had reviewed hundreds of studies, and suggested that if such a study claiming "few biologic effects" was in the literature, they would have reviewed it.

I looked at the DFT's statement and wondered myself from where the phrase "few biologic effects to diesel exhaust exposure" came. The group's press officer promptly sent me its source. It comes from an April 12, 2012 news release from the Health Effects Institute (HEI), a non-profit research center jointly funded by the U.S. EPA and industry. It reported some of the most recent findings. from ACES. Specifically, laboratory rats and mice were exposed for 16 hours per day to diesel engine emissions that meet the U.S. EPA's 2007 exposure standards for fine particulate matter and other pollutants. A review panel overseeing the ACES wrote a commentary to accompany the researchers' report which said:

“Overall, these results indicate that rats exposed to one of three levels of diesel exhaust from a 2007-compliant engine for up to 12 months, for 16 hours per day, 5 days a week, with use of a strenuous operating cycle that was more realistic than cycles used in previous studies, showed few biologic effects related to diesel exhaust exposure.”

I'm glad to know that rats and mice being exposed to very clean diesel engines are not currently showing evidence of biological harm. Perhaps that bodes well for workers in diesel-heavy jobs, like underground mining, trucking, engine maintenance and construction, who, in the years ahead may be working in environments where clean-diesel is used exclusively. In the meantime, the IARC classification of diesel exhaust as a human carcinogens means that employers and regulatory bodies have work to do to reduce workers' and communities' exposure to diesel exhaust.

cmonforton Tue, 06/12/2012 - 08:52

"I want those workers to be as safe as those shrimp" - What we still don't know about Deepwater Horizon response health impacts

lborkowski — Tue, 20 Jul 2010 09:47:25 +0000

"I want those workers to be as safe as those shrimp" - What we still don't know about Deepwater Horizon response health impacts

by Elizabeth Grossman

"I want this seafood to be safe. But I want those workers to be as safe as those shrimp and I'm not just going for funny one-liner," said Senator Barbara Mikulski (D-MD) at the conclusion of the July 15th Senate Appropriations Committee's Commerce, Justice, Science and Related Agencies subcommittee hearing on the use of chemical oil dispersants in the Gulf.

"One might say, 'Well, what's Commerce-Justice doing with public health?'" Mikulski asked rhetorically. "Well, we think [about] water quality, the impact on marine life and seafood and what these dispersants mean to people who are working on the clean-up and who have to live in the Gulf the rest of their lives. We don't want a Gulf War syndrome," she said. "I'm really hot about this, and that's why I said to our colleagues in the executive branch, 'Urgency!' Let's go to the edge of our chair. We need to know more."

What we don't know has, in many ways, become a leitmotif of the Deepwater Horizon disaster. BP the and federal agencies that make up the Deepwater Horizon Unified Command have responded to public concerns by posting copious amounts of information online, including large amounts of sampling data. Nonetheless, information gaps persist - and their continued presence demonstrates the limits of our current system for protecting environmental, public, and workers' health.

Controlled Burns and Particulate Matter
One of the obvious omissions is information regarding particulate matter
(PM) in the air in the vicinity of the Deepwater Horizon rig site, where controlled burns have been conducted since late April. This is of concern because as of July 18th, according Administration-Wide Response summary from the Deepwater Horizon Joint Information Center, 409 controlled burns have been conducted to date, removing more than 11 million gallons of oil from the water. Controlled burn numbers to date from four consecutive days last week give a sense of the frequency of these burns:

July 14: 348
July 15: 377
July 16: 387
July 17: 408

This works out to an average of 15 a day, with a high of 29 burns conducted between July 14 and 15.

Particulate matter is a respiratory irritant that can also affect cardiovascular health, and it is regulated by the EPA. Health effects can include aggravated asthma, chronic bronchitis, irregular heart beat, and non-fatal heart attacks. Both "inhalable coarse particles" of between 2.5 and 10 micrometers (regulated as PM 10) and "fine particles" of 2.5 micrometers or smaller (regulated as PM 2.5) have potential adverse health impacts. Fine particles pose additional concerns as they can become lodged in lung tissue where they can deposit toxic chemicals they may be carrying - polycyclic aromatic hydrocarbons (PAHs) for example.

The EPA and Gulf Coast states regularly monitor for PM, and the EPA has a "BP spill" website where it's been posting its ongoing monitoring of PM along the coast. Yet while there are numerous workers on vessels and platforms in the vicinity of the controlled burns, neither BP, EPA, NIOSH, NOAA nor OSHA has released publicly available data that includes airborne particulate matter for air in the vicinity of the Deepwater Horizon rig site.

This is despite a NOAA paper on in situ burns posted on its oil spill response page that recommends: "Environmental sampling for PM-10 should be conducted in the immediate vicinity of the population that may be affected. We understand, however that the decision to sample and how to sample may depend on the resources available for conducting the sampling and local guidelines."

Another NOAA paper on in situ burns notes that "the burning of oil on water seems to be similar to burning the oil in a furnace or a car, with the exception that the burn is oxygen-starved and not very efficient, so that it generates ample amount of black soot particulates that absorb sunlight and create the black smoke." It also notes that about 5 to 15% of the oil is converted to particulates during a burn and that 1-3% is comprised of NO2, SO2, CO, PAHs, "ketones, aldehydes, and other combustion by-products."

The EPA Gulf Coast onshore air quality monitoring of PM has shown occasional elevated levels, but PM data is largely provided as daily averages and reflects PM from numerous sources, not just those directly related to the Deepwater Horizon incident and response. The EPA has also conducted sampling overflights through its ASPECT program, but these flights are too high to reflect the near-surface air quality that would affect people working on boats and platforms near the rig site, and they have not included particulate sampling. In June, NOAA conducted two low-altitude air monitoring flights and has posted raw data, but according to NOAA spokesperson Linda Joy, it may be months before interpretation of that data is available.

Scope of OSHA's Work
OSHA has been an active presence in the Gulf, but it is limited by the number and quality of existing permissible exposure limits (PELs) and by its existing resources - which are intended to ensure workplace safety nationwide, not only in the Gulf.

In an interview, Deputy Assistant Secretary of Labor for Occupational Safety and Health, Jordan Barab explained that while there are OSHA exposure standards for dust (heavy metals, asbestos, beryllium, and silica dust all pose such hazards) and some occupational standards for diesel particulates, there are no occupational exposure limits for PM comparable to what the EPA has set for ambient air.

The recently released National Institute for Occupational Safety and Health (NIOSH) evaluation of in situ burn work made recommendations about protecting workers from carbon monoxide and sampled for benzene soluble particulates (found not to exceed occupational exposure limits) but not for total particulates. [Note: Sentence updated 7/22 after NIOSH contacted us to clarify that benzene soluble particulates were sampled.]

Existing sampling efforts may be providing insufficient coverage for workers on certain types of vessels, including some closest to the rig site. Vessels involved in work near the rig site - some that are out for 2 to 3 weeks at a time - include privately owned boats engaged by contractors and subcontractors that are working outside of the Vessels of Opportunity (VOOs) program. These boats seem to fall under a different category of oversight than the VOOs and thus far don't appear to have been included in federal government monitoring. When I asked the Coast Guard for a count of such vessels I was told, "Boats like that definitely exist but we don't have a number for you."

"We've been out with people doing in situ burns... and have gone out many times beyond three miles but we are not out at the source monitoring as that's an enormous use of resources," Barab told me. (OSHA's legal jurisdiction for citations extends 3 miles offshore, but it can monitor beyond that limit.) OSHA's sampling is "representative," he explained, and thus far, "We haven't seen much, if any, chemical exposures at all."

"To date, no air sampling by OSHA has detected any hazardous chemical at levels of concern," the agency's website reports. "What frustrates me is that I'm spending so much time explaining that we're seeing such low levels of exposures and I'm wishing that we were taking the same kind of care to make sure that the rest of the workers in the country were not getting exposed to god-knows-what. I wish that everyone was getting the same kind of attention so that we could enforce our totally inadequate PELs [personal exposure limits]," Barab told me.

Health Effects
Barab explains that, in addition to seeing no hazardous levels of exposure in air sampling data, OSHA is not seeing illness reports that would suggest hazardous chemical exposure levels. "To the extent we've been able to look into all cases and that NIOSH has, the majority or plurality have been heat related. That's been the diagnosis and they've been treated by rehydrating people."

NIOSH has been conducting Health Hazard Evaluations (HHE) at the request of BP that include ongoing evaluations of offshore work, explains Allison Tepper, NIOSH chief of Health Evaluation & Technical Assistance Branch. [Note: The rest of this paragraph has been updated (7/22) after NIOSH contacted us to clarify that they have two separate projects, the HHEs and their analysis of BP data.] For the HHE, all data collection, analysis, and interpretation by NIOSH was independent of BP. In a separate project, NIOSH is conducting an ongoing analysis of BP illness and injury data. About this effort, NIOSH's website explains:

The incident forms are filled out by BP safety officials, as opposed to healthcare personnel, and do not contain strict medical diagnoses of injury or illness. This method of employer-generated data collection is standard occupational safety and health practice. BP is sharing the information for each incident, but the data it provides to NIOSH does not include the names of the BP employees, contract workers and volunteers. In addition, since the data is being collected by BP, NIOSH cannot independently verify the accuracy and completeness of the data.

Health hazard evaluations can also be done independently of an employer if requested by three employees, but it does not appear that any such HHE has been initiated to date.

At the Senate hearing on dispersants, both Senator Mikulski and a witness, Louisiana Bucket Brigade executive director Anne Rolfes, raised concerns about possible gaps in monitoring of response-worker health effects. Rolfes pointed out that while state and federal agencies are doing health surveillance and illness and injury record-keeping, because BP has its own medical and first-aid services, there may be additional medical records that are not being shared and to which there is no public access. "I think there needs to be some kind of intervention to get those workers back into the mainstream," said Rolfes, so that their records do not remain entirely private to BP.

"I do think about these workers... and we also think about past experiences where people who did wonderful things and ended up with very serious consequences, and we were told the chemistry was okay or it wasn't a problem," responded Mikulski "And now we have this oil spill and it's one more 'oh well we don't know and we need more research.'
"So," she said, agreeing with the need for open records and better protective measures,
"we're going to do something about it."

"I wish we could channel some of this attention elsewhere," said Barab when we spoke a week before the Senate hearing. "But we're going to stay focused as we don't want to get into a World Trade Center situation."

While these events are clearly very different, the comparison has come up often as a tragic caution about the perils of ignoring response-worker health - and the importance of devoting sufficient resources to protecting workers, wherever they are, from hazardous pollutants.

Elizabeth Grossman is the author of Chasing Molecules: Poisonous Products, Human Health, and the Promise of Green Chemistry, High Tech Trash: Digital Devices, Hidden Toxics, and Human Health, and other books. Her work has appeared in a variety of publications including Scientific American, Salon, The Washington Post, The Nation, Mother Jones, Grist, and the Huffington Post. Chasing Molecules was chosen by Booklist as one of the Top 10 Science & Technology Books of 2009 and won a 2010 Gold Nautilus Award for investigative journalism.

lborkowski Tue, 07/20/2010 - 05:47