Posts Tagged: pollution

Fair weather leads to clean air and farmer dispair

This year's mild summer temperatures - which follows a cool, wet spring - has been a curse for San Joaquin Valley farmers, according to an article in Saturday's Fresno Bee.

On the bright side, a companion story said this year's spring and summer weather is also responsible for cleaner air than usual in the Valley.

In the farm story, reporter Robert Rodriguez devoted significant space to the Valley's raisin crop, which must reach specific sugar levels before an army of 25,000 workers clips grape bunches and arranges them on paper trays in the field to dry.

"The pressure is really going to be on because we will have a shorter amount of time to pick," the article quoted raisin farmer Pete Gonzalez. "Everybody is going to want to go at once. And that's not going to be possible."

Processing tomatoes are typically planted in stages so processors aren't inundated with the entire crop at once. However, the cool spring delayed the first planting. That means some tomatoes may become overripe before processing, reducing their value, the article said.

For the part of his story on cotton, Rodriguez spoke to two University of California Cooperative Extension experts. UCCE farm advisor Dan Munk told the reporter that cotton growers are hoping for a warm fall to finish the crop.

"The more we go into November, the more opportunities we will have for days on end of fog, and that means more moisture and wet cotton," Munk was quoted.

UC integrated pest management advisor Pete Goodell said he is advising growers not to wait too long to harvest.

"Our approach is to go for the shortest season you can," Goodell was quoted. "The later a grower goes, the greater the chances of losing everything."

In the article about clean air, Bee staff writer Mark Grossi reported that the cool spring and mild summer, paired with other factors - such as wind - created poor conditions for the formation of ozone.

"If the San Joaquin Valley violated the federal ozone standard every day for the rest of the summer, this still would be the cleanest season on record," Grossi wrote.

Kern County UCCE hosts air quality study

A 60-foot tower near the UC Cooperative Extension office on South Mt. Vernon Avenue in Bakersfield has been built to hold instruments aloft for air quality studies in the area, the Bakersfield Californian reported.

Researchers from around the country are conducting the studies to gain a deeper understanding of the environment and to inform air quality regulatory policy.

"You need to measure what's in the air, and then from that you go back and look at crafting regulatory policy," UCCE farm advisor John Karlik was quoted. "But science has to precede policy."

The tower is hosted by the UC Cooperative Extension and funded by the California Air Resources Board.

Bakersfield was chosen as a site for the project, which began in May and runs through the end of June, because of its problems with air quality and its relatively strong sources of atmospheric compounds, the article said.

The participating scientists - representing UC Berkeley, University of Wisconsin and University of Miami - have already begun assessing data.

"It's all about how we put those data into a larger framework," Karlik was quoted. "We think it's of broader public interest."

Valley ozone story takes off

Research by UC Davis scientists that revealed a substantial amount of San Joaquin Valley ozone is generated by animal feed is getting wide coverage in the news media. Google News reported 126 articles on the subject.

Many newspapers ran the Associated Press version of the story, written by Fresno-based Tracie Cone. She reported that the study — funded by the U.S. Department of Agriculture, California Air Resources Board and the San Joaquin Valley Air Pollution Control District — was initially intended to measure the impact of animal manure, urine and flatulence on ozone levels.

However, the researchers discovered that millions of tons of fermenting cattle feed bears greater responsibility.

Mark Grossi of the Fresno Bee noted in his story that the study was published last month in the journal Environmental Science & Technology. This week's flurry of interest was generated by an April 21 news feed from the American Chemical Society press office. ACS publishes the journal.

In his story, Grossi wrote that the cattle feed explains only half of the Valley's ozone problem. The other half, Nitrogen oxide, or NOx, comes from vehicles. San Joaquin Valley Air Pollution Control District believes NOx is more important to control, the Bee article said.

Meanwhile, Capital Press reported yesterday that the U.S. Environmental Protection Agency has rescinded its long-standing exemptions for agriculture under emission-control rules.

"Air quality in the San Joaquin Valley is consistently among the worst in the nation," said Deborah Jordan, director of the Air Division for the EPA's Pacific Southwest region, in a statement. "New and modified facilities will now be subject to the most stringent requirements, which will contribute to the health of our communities."

A dairy cow eats its rations.

Animal feed generates lots of valley ozone

Scientists have been puzzled by the fact that the San Joaquin Valley often suffers high ozone levels even though the mostly rural, agricultural domain has fewer cars and trucks than big cities. Research by UC Davis scientists is now showing that some of the ozone in the valley is being generated by fermented animal feed, according to a story posted yesterday on the website Science News.

While ozone provides a protective barrier for the earth in the stratosphere, it is an unwelcome molecule to have around where people are breathing. Ozone (O₃) is a powerful oxidizing agent, far stronger than O₂. It can harm lung function and irritate the respiratory system.

The UC Davis team, led by environmental engineer Cody Howard, tested seven types of animal feed in a one-meter-square tented chamber, according to writer Janet Raloff, author of the Science News story. They added a mix of gases that matched the valley’s air and simulated sunlight with lamps. The result was lots of ozone.

Corn silage generated about 125 parts per billion ozone, alfalfa silage a little less, and mixed oat-wheat silage 210 ppb, Raloff reported. These emissions pale in comparison to cars. However, because the San Joaquin Valley has so much silage to feed its animal agriculture industry, the feed appears to be the single biggest contributor to the region’s ozone problem, the story said.

Cars and light-duty trucks in the valley can generate 13 metric tons of ozone per day, while feed for the valley’s 10 million head of dairy cattle can produce 24.5 million tons of ozone per day.

Corn silage livestock feed.

Polluted air may contribute to farmworkers diabetes risk

The Sacramento Bee picked up on a UC news release about the most recent issue of California Agriculture journal, which said more than 1 million California farmworkers face a higher risk of diabetes and respiratory disease because of poor air quality.

The news release says California's Central Valley has the highest recorded levels of particulate matter in the country. The polluted air results in increased rates of asthma and other respiratory illnesses. In addition, the release said research points to possible environmental links between pesticide exposure and the risk of diabetes.

In a sample of 1,300 Mexican Americans who participated in the Hispanic Health and Nutrition Examination Survey, conducted from 1982 to 1984, higher levels of organochlorine compounds, which are found in pesticides, were observed in the blood of adults with self-reported diabetes compared to those without diabetes, according to the Cal Ag article.

"However, due to the cross-sectional design of the study, it is not clear whether there is a causal relationship between pesticide exposure and diabetes, or what the nature of that relationship may be," according to the article.

That said, perhaps the Sacramento Bee headline - "Farmworker diabetes risk linked to bad air" - is overstated.

The UC release also appeared on Yubanet.com.

The January to March issue of California Agriculture journal.

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