Tag Archives: exposure

Exposure to air pollution in infancy alters gut microorganisms, may boost disease risk [Preventive Steps]

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Exposure to air pollution in the first six months of life impacts a child’s inner world of gut bacteria, or microbiome, in ways that could increase risk of allergies, obesity and diabetes, and even influence brain development, suggests new CU Boulder research.

“This study adds to the growing body of literature showing that air pollution exposure, even during infancy, may alter the gut microbiome, with important implications for growth and development,” said senior author Tanya Alderete, assistant professor of Integrative Physiology at CU Boulder.

At birth, an infant hosts little resident bacteria. Over the first two to three years of life, exposure to mother’s milk, solid food, antibiotics and other environmental influences shape which microorganisms take hold. Those microbes, and the metabolites, or byproducts, they produce when they break down food or chemicals in the gut, influence a host of bodily systems that shape appetite, insulin sensitivity, immunity, mood and cognition. While many are beneficial, some microbiome compositions have been associated with Chrohn’s disease, asthma, type 2 diabetes, and other chronic illnesses.

Air pollution/photo:en.wikipedia.org

“The microbiome plays a role in nearly every physiological process in the body, and the environment that develops in those first few years of life sticks with you,” said first author Maximilian Bailey, who graduated in May with a master’s in Integrative Physiology and is now a medical student at Stanford University.

Boosting inflammation

For the study, the researchers obtained fecal samples from 103 healthy, primarily breast-fed Latino infants enrolled in the Southern California Mother’s Milk Study and used genetic sequencing to analyze them.

Using their street addresses and data from the U.S. Environmental Protection Agency’s Air Quality System, which records hourly data from monitoring systems, they estimated exposure to PM2.5 and PM10 (fine inhalable particles from things like factories, wildfires and construction sites) and Nitrogen Dioxide (NO2), a gas largely emitted from cars.

“Overall, we saw that ambient air pollution exposure was associated with a more inflammatory gut-microbial profile, which may contribute to a whole host of future adverse health outcomes,” said Alderete.

For instance, infants with the highest exposure to PM2.5 had 60% less Phascolarctobacterium, a beneficial bacterium known to decrease inflammation, support gastrointestinal health and aid in neurodevelopment. Those with the highest exposure to PM10 had 85% more of the microorganism Dialister, which is associated with inflammation.

infant-small child/photo:en.wikipedia.org

Infants are particularly vulnerable to the health hazards of air pollution because they breathe faster and their gut microbiome is just taking shape.

“This makes early life a critical window where exposure to air pollution may have disproportionately deleterious health effects,” they write.

Meantime, Alderete advises everyone to take these steps to reduce their exposure to both indoor and outdoor pollutants:

  • Avoid walking outdoors in high-traffic zones
  • Consider a low-cost air-filtration system, particularly for rooms children spend a lot of time in
  • If you are cooking, open the windows
  • And for new moms, breastfeed for as long as possible

“Breast milk is a fantastic way to develop a healthy microbiome and may help offset some of the adverse effects from environmental exposures,” Alderete said.

Air pollution is more dangerous for women than men: Study

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The impact of breathing diesel exhaust fumes may be more severe for females than males, according to new research that will be presented at the European Respiratory Society International Congress in Barcelona, Spain [1].

Researchers looked for changes in people’s blood brought about by exposure to diesel exhaust. In both females and males, they found changes in components of the blood related to inflammation, infection and cardiovascular disease, but they found more changes in females than males.

The research was presented by Dr Hemshekhar Mahadevappa, from the University of Manitoba, Winnipeg, Canada and was a collaboration between two research groups led by Professor Neeloffer Mookherjee at the University of Manitoba and Professor Chris Carlsten at the University of British Columbia, Vancouver, Canada. Dr Mahadevappa told the Congress: “We already know that there are sex differences in lung diseases such as asthma and respiratory infections.

Air pollution/Photo:en.wikipedia.org

Research showed that breathing diesel exhaust creates inflammation in the lungs and has an impact on how the body deals with respiratory infections. In this study, we wanted to look for any effects in the blood and how these differ in females and males.”

The study involved ten volunteers, five female and five male, who were all healthy non-smokers. Each volunteer spent four hours breathing filtered air and four hours breathing air containing diesel exhaust fumes at three different concentrations – 20, 50 and 150 micrograms of fine particulate matter (PM2.5) per cubic metre – with a four-week break in between each exposure.

Volunteers donated blood samples 24 hours after each exposure and the researchers made detailed examinations of the volunteers’ blood plasma. Plasma is the liquid component of the blood that carries blood cells as well as hundreds of proteins and other molecules around the body. Using a well-established analysis technology called liquid chromatography–mass spectrometry, the researchers looked for changes in the levels of different proteins following exposure to diesel exhaust and compared the changes in females and males.

Airpollution/Photo:en.wikipedia.org

Comparing the plasma samples, the researchers found levels of 90 proteins that were distinctly different between female and male volunteers following exposure to diesel exhaust. Among the proteins that differed between females and males, were some that are known to play a role in inflammation, damage repair, blood clotting, cardiovascular disease and the immune system. Some of these differences became clearer when volunteers were exposed to the higher levels of diesel exhaust.

Professor Mookherjee explained: “These are preliminary findings, however they show that exposure to diesel exhaust has different effects in female bodies compared to male and that could indicate that air pollution is more dangerous for females than males.

“This is important as respiratory diseases such as asthma are known to effect females and males differently, with females more likely to suffer severe asthma that does not respond to treatments. Therefore, we need to know a lot more about how females and males respond to air pollution and what this means for preventing, diagnosing and treating their respiratory disease.”

Air pollution/photo:en.wikipedia.org

Professor Zorana Andersen from the University of Copenhagen, Denmark, is Chair of the European Respiratory Society Environment and Health Committee and was not involved in the research. She said: “We know that exposure to air pollution, especially diesel exhaust, is a major risk factor in diseases such as asthma and chronic obstructive pulmonary disease. There is very little we can do as individuals to avoid beathing polluted air, so we need governments to set and enforce limits on air pollutants.