Archives for posts with tag: disease

From Reuters:

In a study of more than 4,000 black women in Los Angeles, those who lived in areas with higher levels of traffic-related air pollution were at increased risk of developing diabetes and high blood pressure.

The researchers, led by Patricia Coogan at Boston University, found that black women living in neighborhoods with high levels of nitrogen oxides, pollutants found in traffic exhaust, were 25 percent more likely to develop diabetes and 14 percent more likely to develop hypertension than those living in sections with cleaner air.

Previous research has linked air pollution to health problems such as diabetes, stroke, heart disease and even higher rates of death.

“The public health implications are huge,” said Dr. Jiu-Chiuan Chen, who studies the effects of air pollution at the University of Southern California Keck School of Medicine in Los Angeles, especially for black women, who have higher rates of diabetes and high blood pressure than white women. He was not involved in the current work.

Forty-four percent of all black women in the U.S. have high blood pressure and about 11 percent have diabetes compared with 28 percent and roughly seven percent, respectively, of white women, according to the Centers for Disease Control and Prevention.

Black Americans also experience higher levels of air pollution than white Americans, according to the study authors.

For their investigation, published in Circulation, the researchers followed participants in the ongoing Black Women’s Health Study for 10 years. The women were mainly recruited from subscribers to Essence magazine, and none had diabetes or high blood pressure when the study began in 1995.

Over the course of a decade, 531 women developed high blood pressure and 183 women were diagnosed with diabetes.

The findings on their relative risks for those conditions take into account several other potential influences, including how heavy the women were, whether they smoked and other stressors, including noise levels at participants’ homes.

Although researchers measured average pollution levels near participants’ homes for only one year of the ten-year study, Coogan told Reuters Health that air pollution patterns remained relatively constant over the entire study period.

While Coogan and her colleagues estimated nitrogen oxide concentrations near participants’ homes, they did not account for commuting habits or exposure to air pollution at work. According to the researchers, Americans, on average, spend about 70 percent of their time at home.

In addition to measuring nitrogen oxides, a proxy for traffic pollution, the researchers evaluated levels of fine particulate matter. Many sources contribute to this type of air pollution, including traffic, power plants and industrial processes.

Women who lived in areas with higher fine particulate exposures also faced an increased risk of diabetes and high blood pressure, although statistically the link was weak and could have been due to chance.

Previous reports have suggested that air pollution particles small enough to make their way into the blood stream may contribute to a narrowing of blood vessels, which can lead to high blood pressure and reduce sensitivity to insulin.

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From Science News:

In a new study of people with diabetes, blood pressure rose in rough lockstep with short-term increases in soot and other microscopic air pollutant particles. Such transient increases in blood pressure can place the health of the heart, arteries, brain and kidneys at risk, particularly in people with chronic disease.

In contrast, when ozone levels climbed, blood pressure tended to fall among these people, independent of particulate levels. “And that was certainly not what we expected,” notes study coauthor Barbara Hoffmann of the Leibniz Research Institute for Environmental Medicine in Düsseldorf, Germany.

Temperature also had an independent effect: A five-day average increase of 11.5 degrees Celsius, for instance, was associated with a small drop in blood pressure, Hoffmann and her colleagues report online October 21 in Environmental Health Perspectives.

Earlier studies suggested that particulates of the size measured in this study — just 2.5 micrometers in diameter — can hike blood pressure, particularly in people with diabetes.

To further investigate, Hoffman and her colleagues followed 70 Boston-area men and women, ages 40 to 85, with long-standing type 2 diabetes. All lived within 25 kilometers of a major air pollution monitoring station. Each participant submitted to repeated health tests at intervals of several weeks, which the researchers matched up with air pollution values from the preceding five days.

The team found pollution-related changes primarily in systolic blood pressure, the pressure exerted by the pumping action of each heartbeat. Systolic pressure is the top number in a blood pressure reading.

Since levels of particulates and ozone don’t necessarily track, one type of air pollutant cannot be expected to cancel out blood pressure alterations posed by the other, the researchers say. And ozone-associated drops in blood pressure aren’t necessarily beneficial. In fact, Hoffmann says, they offer additional evidence of a diabetes-related impairment in the ability of blood vessels to quickly adjust to changing environmental conditions by relaxing or constricting.

Changes in ozone and air pollution levels had no effect on people whose blood sugar was well controlled. Similarly, people with healthy baseline blood pressure readings exhibited little vulnerability to pollution.

“So especially if you want to positively influence your risk from air pollution,” Hoffmann says, “it seems a very good idea to tightly control your blood pressure and your blood sugar.”

The fact that a rise in concentrations of near-nanoscale particulates as small as 3.5 micrograms per cubic meter of air could raise systolic blood pressure “corroborates that current levels of particulate matter disrupt blood pressure control,” says physician Robert Brook of the Division of Cardiovascular Medicine at the University of Michigan Medical School in Ann Arbor. The new data, he maintains, confirm that short-term inhalation of fine airborne particulates at ambient levels — and perhaps traffic-related soot in particular — “have small but potentially clinically meaningful effects.”

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From Environmental Health News:

Cumulative risk assessment posits that multiple agents work together to induce disease and that multiple stressors therefore must be considered in order to gain a true understanding of why adverse health effects occur.  Now a small but growing number of scientists are pushing the envelope by investigating whether chronic psychological stress might be one of those factors, enhancing a child’s vulnerability to certain chemical exposures and contributing to effects that later show up as asthma, neurodevelopmental disorders, cardiovascular disease, obesity, cancer, and other problems. These researchers are also starting to identify biomarkers that may shed light on the mechanisms by which psychological stress acts on a child’s developing immune system and brain to modify or enhance the response to certain pollution exposures such as
traffic-related air pollutants and lead.

“We really don’t know how broadly such interactions may occur across chemicals. They are much more likely to occur when the chemical itself acts directly upon stress systems,” says Deborah Cory-Slechta, a professor of environmental medicine at the University of Rochester School of Medicine & Dentistry.

“We know some chemicals that interact with stress, such as lead exposure, but we don’t know which others do.”

Observations of links between stress and disease date back to at least the twelfth century, when the philosopher Maimonides cited emotional upset as a factor in asthma. But proving such links poses a significant challenge, says Malcolm P. Cutchin, a professor at the School of Medicine of the University of North Carolina at Chapel Hill. “Much has been hypothesized about the linkages, but we are just now beginning to tease out relationships and understand the processes,” Cutchin says. As researchers have learned more about techniques that can identify chemical and stress exposures in the human body, they have begun to apply techniques to estimate how people respond to stress and how that response, if it goes awry, can facilitate the development of diseases.

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From The Telegraph:

Scientists at the Department of Obstetrics and Gynaecology, at the University of Sherbrooke Hospital Centre in Quebec, took dozens of samples from women.

Traces of the toxin were found 93 per cent of the pregnant mothers and in 80 per cent of the umbilical cords.

The research suggested the chemicals were entering the body through eating meat, milk and eggs from farm livestock which have been fed GM corn.

The findings appear to contradict the GM industry’s long-standing claim that any potentially harmful chemicals added to crops would pass safely through the body.

To date, most of the global research which has been used to demonstrate the safety of GM crops has been funded by the industry itself.

It is not known what, if any, harm the chemicals might cause but there has been speculation it could lead to allergies, miscarriage, abnormalities or even cancer.

One of the researchers told the scientific journal Reproductive Toxicology: “This is the first study to highlight the presence of pesticides associated with genetically modified foods in maternal, foetal and nonpregnant women’s blood.”

Pete Riley, the director of GM Freeze, a group opposed to GM farming, described the research as “very significant”.

The Agriculture Biotechnology Council, which speaks for the GM industry, has questioned the reliability and value of the research.

Dr Julian Little, its chairman, said: “Biotech crops are rigorously tested for safety prior to their use and over two trillion meals made with GM ingredients have been safely consumed around the world over the past 15 years without a single substantiated health issue.”

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From CNN:

Some Gulf Coast residents and former clean-up workers are suffering from an array of mysterious illnesses, according to a Louisiana physician who has treated dozens of patients complaining of similar symptoms.

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