Booster Shots

Oddities, musings and news from the health world

Category: pollution

Particulate air pollution is a modifiable risk factor for heart disease, heart association says

May 10, 2010 |  1:10 pm

The evidence linking particulate air pollution to cardiovascular disease and deaths has strengthened in recent years and high levels of the pollutant should be considered a modifiable risk factor for cardiovascular disease along with such well-known factors as high blood pressure, high cholesterol, obesity and diabetes, the American Heart Assn. said Monday.

The very fine particles in the air, produced by fossil fuel combustion in industry, automobiles and power generation, among other sources, can trigger heart attacks and other problems in susceptible individuals within hours to days of exposure and can shorten lives by months to years, the statement said. In fact, health consequences to the cardiovascular system from air pollution are greater than those due to lung diseases, the statement concluded. Those who are most susceptible to its effects should take steps to minimize their exposure when pollution levels are high, such as reducing strenuous activities, avoiding commuting and staying indoors.

The association first addressed the link between air pollution and cardiovascular disease in 2004, concluding that exposure contributes to increased disease and mortality and that long-term exposure shortens lifetimes.

But "the body of evidence has grown and been strengthened substantially" since then, the statement said, and the links are now much clearer.  Although all forms of air pollution are troublesome, the best evidence involves fine particulates -- those that are less than 2.5 micrometers in diameter. Such particulates can be inhaled deeply into the lungs, make their way into the bloodstream and trigger inflammation and other problems.


The increased risk is greatest among those who are susceptible to cardiovascular disease but who are not necessarily critically ill. That includes the elderly, people with preexisting cardiovascular disease and perhaps those with diabetes. Women and the obese may also be at higher risk. Short-term exposure can trigger heart attacks and similar acute problems, but long-term exposure can also produce disease and deaths. The effects on death are better documented, the committee that prepared the report concluded, because the effects of long-term exposure on disease have not been studied as thoroughly.

There does not appear to be any discernible safe threshold for exposure to such pollutants, but reductions in particulate levels can lower cardiovascular mortality in a time frame as short as a few years.

The best way for patients to protect themselves from the harmful effects of air pollution is to control their other risk factors, which will lessen their susceptibility. Physicians should also counsel patients about steps they can take to minimize their exposure during periods of high pollution. The best way is to stay indoors, especially in homes equipped with filters that will remove the particulates. If travel is necessary, keep car windows closed and set the heating/air conditioning system to recycle inside air rather than drawing in air from outside. Filters for cars are also available that will remove many of the particulates.

The statement was prepared by a multidisciplinary panel headed by Dr. Robert D. Brook of the University of Michigan. The panel considered all research on human health effects conducted in the last six years to reach its conclusions.

-- Thomas H. Maugh II

Heavy air pollution, such as in Mexico City last week, can not only trigger heart attacks but increase the long-term risk of cardiovascular disease and death. Credit: Sashenka Guierrez / EPA

Smog is ugly, and its health effects aren't very pretty either

April 28, 2010 |  8:27 pm

Air Sure, the weather here is great, but .... The American Lung Assn. has released its annual report card on the nation's air quality, and it's good news only for those who take dark delight in the stereotype  of Los Angeles as perpetually cloaked in smoggy, choking, stifling air.

Once again, the metropolitan area came out on top  (bottom?) in terms of ozone. Bakersfield won the short-term particle pollution competition (although other California areas put up a good fight) and the Phoenix-Mesa-Scottsdale area nailed the year-round particle pollution competition.

Here's the story from Wednesday's Los Angeles Times: Los Angeles is still the nation's smoggiest city

The association's California policy director, Bonnie Holmes-Gen, is quoted as saying: "This is not just a nuisance or a bother.... Thousands of people are being rushed to emergency rooms. Thousands of people are dying early as a result of air pollution.... It is a crisis."

Perhaps you're not moved. Perhaps you're starting to tune out the laments about the quality of Los Angeles air. That's understandable in a way. But check out our coverage exploring the health effects of bad air.

- Take a deep breath -- more bad news on air pollution: The consequences of breathing bad air is linked to appendicitis and ear infections, new studies indicate.

Smoggy day? Exercise caution: Poor air quality can trip up even the healthiest outdoor buff. Pay attention to daily reports and your body's reactions.

It's worse than dirty: L.A.'s notorious air pollution is hardest on kids. The closer to a freeway they live, play or attend school, the more likely it is that their developing lungs' capacity will be reduced.

Not moved? What if we were to tell you that pollution is making us fat? (Some people have actually suggested this.) 

Here's the thinking behind that proposed connection, explained in the article We're fat because...

(We don't blame you for being unconvinced -- but still, it's probably best not to simply accept pollution as a fact of life.)

Here's the State of the Air report and a synopsis of health risks. Then there's this roundup on pollution information from MedlinePlus. It includes links to clinical trials exploring the effects of bad air; separate looks at nitrogen dioxide, lead, smoke and other pollution components; even a plain-English  guide to the Clean Air Act. 

-- Tami Dennis

Photo: Deep breaths are only relaxing if they don't make you cough.

Credit: Associated Press 

As EPA moves to crack down on smog, here's a closer look at its physical toll

January 8, 2010 |  9:41 am


Photo: Sometimes, breathing deeply may not be a good thing. Shown here, Downtown Los Angeles shrouded in smog. Credit: Francine Orr / Los Angeles Times

Dirty air can't actually be good for us. That seems logical enough. But many people may not know just how bad it can be. With the Environmental Protection Agency proposing stricter rules to improve the nation's air quality, we offer a quick refresher on the reasons for such concern. 

-- In this recent Los Angeles Times story, which began with new studies linking air pollution to appendicitis and ear infections, writer Jill Adams reports:

Research on air pollution has been conducted worldwide for decades and is part of the basis for government regulation of air quality. Study after study has found more hospitalizations and higher death rates when certain pollutants are high. In addition to respiratory effects, research has established that air pollution increases the risk of cardiovascular events such as arrhythmia, heart attack and stroke, and the incidence of certain cancers.

Read more.

-- Here, staff writer Jeannine Stein explores the hazards to Angelenos, and outdoor exercisers in particular. She writes about the potentially hazardous effects of gasping dirty air:

Those effects, which can include coughing, a burning sensation in the lungs and shortness of breath, come from inhaling various particles from smoke and exhaust that make lung tissues swell and airway passages narrow. Brisk exercise exacerbates the effects (when and how severe those are vary from person to person). Because muscles need more oxygen to work, breathing rates increase by about seven times.... As a result, the lungs take in and expel double to triple the normal amount of air -- dramatically increasing their exposure to pollutants." This is especially problematic for people with coronary artery disease.

Read more.

-- Because air quality is often worse near freeways, Erin Cline Davis explores pollution's effects on those who live nearest L.A.'s automobile-heavy areas. She notes:

Everyone is familiar with the gray-brown haze that often blankets Los Angeles, and the fact that the city consistently ranks as one of the most polluted in America. But what many may forget is that the dismal reports of L.A.'s air pollution only capture the average amounts of toxins in the air, and that some places within the urban sprawl are far dirtier than others. Official numbers do not take into account the fact that pollutants are at much higher levels within a few hundred feet of the freeways that crisscross the city -- and for the adults and kids who live, work or go to school there, the effects add up.

Read more.

-- The California Environmental Protection Agency offers this look at the health effects of air pollution and these measures of current and recent air quality. Thursday wasn't a stellar one for the South Coast Air Basin.

As for the new move to improve air quality, here's that story from today's Los Angeles Times: EPA proposes nation's strictest smog limits ever

-- Tami Dennis

Softeners in plastics may affect masculinity in young boys, study says

November 15, 2009 |  9:10 pm

Boys born to mothers who have above-normal levels of the controversial chemicals known as phthalates in their urine are less likely to exhibit masculine behavior, a new study has found. Phthalates, which block the activity of male hormones such as androgens, could be altering masculine brain development, according to Shanna H. Swan, a professor of obstetrics and gynecology at the University of Rochester Medical Center and lead author of the new report.

Phthalates are widely used to soften plastics such as polyvinyl chloride and make them flexible. They are used in food packaging, vinyl and plastic tubing, household products and many personal care products, such as soaps and lotions. Although the Food and Drug Administration considers them safe, a 2008 federal law banned the use of six different types in toys such as teethers, bath items, soft books, dolls and plastic figures.Boyplay

Swan had previously shown that some small boys and toddlers exposed to phthalates in the womb had subtle changes in the size and anatomy of their genitals. Researchers are planning to follow those boys into adulthood to determine if  there are changes in their sperm count or if they have reproductive problems.

In the new study, Swan and her colleagues focused on a small group of women who gave birth between 2000 and 2003. Urine samples collected in the 28th week of pregnancy were analyzed for phthalates by the Centers for Disease Control and Prevention.

When the children were between 3½ and 6½ years of age, the team administered a standard questionnaire called the Preschool Activities Inventory or PSAI that assessed the types of toys children selected (trucks versus dolls, for example), activities such as rough-and-tumble play and other characteristics. They will report Monday in the International Journal of Andrology that the boys whose mothers had the highest levels of the chemical in their urine were the least masculine in their playtime activity. Girls were not affected.

"Our results need to be confirmed, but are intriguing on several fronts," Swan said. "Not only are they consistent with our prior findings that link phthalates to altered male genital development, but they also are compatible with current knowledge about how hormones mold sex differences in the brain, and thus behavior. We have more work to do, but the implications are potentially profound."

— Thomas H. Maugh II

Boys who were exposed to phthalates in the womb were less likely to exhibit masculine play, according to a new study. Credit: Los Angeles Times / Al Schaben

High exposure to BPA causes sexual dysfunction in men, researchers say

November 10, 2009 |  9:00 pm

High levels of occupational exposure to the controversial chemical bisphenol A, more commonly known as BPA, causes erectile dysfunction, loss of desire and difficulty ejaculating, U.S. and Chinese researchers reported today. Similar problems have been reported in rodents, but this is the first study to show such effects in humans, and the findings are likely to further inflame the debate over the chemical.

BPA was first developed in the 1930s as a synthetic estrogen analog, similar to diethylstilbestrol, but it soon came to be used in the manufacture of plastics, particularly polycarbonates. It is now found in a wide variety of products, including baby bottles, water bottles and the linings of cans used for food and beverages. Some of the chemical is known to seep out of such products, and more than 90% of Americans have BPA in their urine. Consumer Reports published a study recently showing that high levels of BPA were found in many food products, but that study has been heavily criticized.

The Food and Drug Administration recently decided tentatively that BPA was safe at levels now found in the population, but that conclusion was refuted by its science advisory board. Nonetheless, many localities have banned BPA in baby bottles, and manufacturers have said they will take it out of products meant for infants.Babybottle

A variety of BPA animal studies has suggested that the chemical has many health effects, including infertility, weight gain, behavioral changes, early onset of puberty, cancer and diabetes. "Critics dismissed all the animal studies, saying, 'Show us the human studies,' " said Dr. De-Kun Li, a reproductive endocrinologist at Kaiser Permanente's Division of Research in Oakland and the lead author of the new study. "Now we have a human study, and this can't just be dismissed."

Li and his colleagues in the U.S. and China studied 634 workers in Chinese factories: 230 of them were exposed to high levels of BPA on their jobs, and 404 worked in factories where there was no exposure. The team measured air levels of BPA, ingestion and other measures of contamination, and monitored urine levels as well. They also questioned the workers about their sexual experiences.

The team reported online in the journal Human Reproduction that, on average, the workers exposed to BPA had a greater than fourfold increased risk of erectile dysfunction, a fourfold risk of low sexual desire, and a more than sevenfold increased risk of ejaculation difficulties. On average, the men had about 50 times the average urinary BPA concentration of American males, but the team found that the frequency of problems rose with increasing levels of the chemical.

"Because the BPA levels in this study were very high, more research needs to be done to see how low a level of BPA exposure may have effects on our reproductive system," Li said. "This study raises the question: Is there a safe level for BPA exposure, and what is that level? More studies like this, which examine the effects of BPA on humans, are critically needed to help establish prevention strategies and regulatory policies."

The study was funded by the U.S. National Institute of Occupational Safety and Health.

-- Thomas H. Maugh II

Photo: Baby bottles have been among the most controversial products containing BPA. Credit: Don Bartletti / Los Angeles Times

The toll of living in a concrete jungle

October 15, 2009 |  6:00 am

Green People who live in rural areas appear to have a major health advantage compared with city-dwellers. Living close to green space improves one's mental and physical health across a wide range of disease states, according to a new study.

Researchers in the Netherlands looked at the health records of people registered with 195 family doctors across the country. The percentages of green space within a 1-kilometer and 3-kilometer radius (that's 0.68 of a mile to 1.86 miles) of their homes were calculated.

Overall, the prevalence of 15 of 24 diseases was lower among people living with more green space, particularly those with more green space within 1 kilometer. The prevalence of anxiety disorders among those living in an area containing 10% green space within a 1-kilometer radius was 26 per 1,000. For those living in an area with 90% green space, the rate was 18 per 1,000. Depression rates in the first group were 32 per 1,000 compared with 24 per 1,000 for people living around more green.

The researchers also found that the impact of living near green space was greatest for people who spent the most time at home, including children and people of lower socioeconomic status.

The presence of green space may influence health through several mechanisms, the authors said. It could assist with recovery from stress, allow for more social interactions with neighbors and create more opportunities for physical activity. Air quality may be better, too.

"Our study shows that the role of green space in the living environment for health should not be underestimated," the authors wrote.

The study was published today in the Journal of Epidemiology and Community Health.

-- Shari Roan

Photo credit: Bryan Chan / Los Angeles Times

Cleaner homes, even cave-dwellers would have agreed, are good

July 28, 2009 |  4:40 pm

Campfire The recent Health section story "In search of a nontoxic home" detailed the lengths to which some people will, or must, go to create a healthful, safe home. A "refuge," the story calls it.

But the writer of that piece, Karen Ravn, also noted that humans have always had a vested interest in keeping the air in their homes clean.

She wrote in an earlier, less-condensed version of the story:

"Very soon after they discovered fire, our prehistoric progenitors must have discovered that smoke smelled bad and stung their eyes and throats.

'A caveman probably figured out that it was better to build a fire in front of his cave than inside it,' said Dr. Roger McClellan, an advisor in inhalation toxicology and human health risk analysis in Albuquerque.

After all, there was plenty of air outside to dilute the smoke, but inside the cave there wasn’t -- which illustrates why, still today, outside air is generally cleaner than inside air: There’s simply more of it to dilute whatever stuff gets into it."

Ravn tells us how to clean up the air in our homes in the related stories in that package:

How to have healthier air in your home

Make the bedroom your sanctuary

Beware these household chemicals

-- Tami Dennis

Photo: Sure, campfires are nice outside. Our ancestors had to live with the things. 

Credit: Allen J. Schaben  / Los Angeles Times


How smoggy was it?

June 19, 2009 |  4:36 pm

Before the Beijing Summer Olympics in 2008, athletes braced themselves for extreme air pollution levels they hoped wouldn't hamper their performance. In anticipation of the games, Chinese authorities instituted a number of measures to improve the air quality, including reducing the number of cars on the road, closing factories that contributed to the pollution and cutting back on construction. More factories in surrounding areas were also closed.

The results? Not so good.

K4qjtync Air samples were collected from atop the seven-story geology building of Peking University for two weeks before the Olympics, two weeks during the games and a month afterward. Researchers then analyzed the particulate matter. At the same time they collected meteorological data, including wind speed and direction, precipitation and temperature. Results from the analysis of the particulate matter were compared to air pollution data taken by the Beijing Environmental Protection Bureau.

The researchers (from Oregon State University and Peking University) discovered that 81% of the time, levels of coarse particulate matter exceeded safe levels as determined by the World Health Organization. And a whopping 100% of the time they reached unacceptable levels for smaller particulate matter, considered more dangerous because it can be inhaled more easily into the lungs.

The levels were higher than what the Beijing Environmental Protection Bureau released, because of differences in the methods of measurement. Levels exceeded an average day in Los Angeles by two to four times, and were also higher than pollution levels during previous Olympics in Athens; Atlanta; and Sydney, Australia.

Despite this, study coauthor Staci Simonich, associate professor of environmental and molecular toxicology at OSU, said that so far no evidence exists showing that athletes or spectators suffered any health problems because short-term exposure of the pollution. It's undoubtedly another story for the millions of Chinese who have to live with poor air quality day to day. However, researchers noted that last fall, particulate matter air pollution in Beijing was as much as 27% lower than a year earlier. That, they say, may in part be due to economic downturns and less industrial output. The study appears in the journal Environmental Science and Technology.

-Jeannine Stein

Photo of Beijing from July 2008. Credit: Jean Chung / For The Times


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