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Indoor air and outdoor pollution

July 11, 2025 By EarthWise Leave a Comment

The majority of us spend about 80% of our time indoors. The quality of the air that we breathe depends on the age and type of building we occupy along with any sources of indoor pollution that may exist and, ultimately, the quality of the air outdoors. The HVAC used to heat, ventilate, and cool the building plays an important role.

The College of Engineering at the University of Utah used its Salt Lake City campus as a living laboratory to explore how outdoor air pollution affects indoor air quality. Specifically, the nature of outdoor pollution sources strongly affected how effectively HVAC systems prevented external sources from getting into buildings.

Of particular concern is fine particulate matter with a diameter of less than 2.5 microns. These PM 2.5 particles can penetrate deeply into lungs, potentially causing health problems like respiratory irritation and heart disease.

There are multiple sources of PM 2.5. The Utah study found that wildfire smoke had four to five times more PM 2.5 infiltration into buildings than pollution from inversions and wind-driven dust events.

An additional finding was that commercial HVAC systems that use air-side economizers are much less effective at keeping out particulate matter. These systems use special duct and damper systems that reduce energy use by drawing air from outdoors when temperature and humidity levels are optimum.

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Does outdoor air pollution affect indoor air quality?

Photo, posted June 15, 2024, courtesy of Peter Burka via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Amphibians and climate change

April 7, 2025 By EarthWise Leave a Comment

Amphibians are a group of vertebrate animals that include frogs, toads, and salamanders. They are unique for their ability to live both in water and on land during different stages of life. Amphibians play a crucial role in ecosystems, often serving as both predators and prey in food webs.

Amphibians are the world’s most at-risk vertebrates, with more than 40% of species listed as threatened. They are cold-blooded creatures and rely on external sources to regulate their body temperature. But needing to regulate their body heat this way makes amphibians particularly vulnerable to temperature change in their habitats.

Researchers from the University of New South Wales in Australia can now predict the heat tolerance of 60% of the world’s amphibian species. This new tool will allow scientists to better identify which amphibian species and habitats will be most impacted by climate change.

The study’s landmark findings, which were recently published in the journal Nature, found that 2% of amphibian species are already exposed to overheating in shaded terrestrial conditions. According to the research team, a 4°C global temperature increase could push 7.5% of amphibian species beyond their physiological limits.

Local amphibian extinctions can trigger ecological repercussions, including reshuffling community compositions, eroding genetic diversity, and impacting the food chain and overall ecosystem health.

The researchers highlight the importance of vegetation and water bodies in protecting amphibians during heat waves, and emphasize the need to provide adequate water and shade during future conservation efforts.

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The pot is already boiling for 2% of the world’s amphibians: new study

Photo, posted October 8, 2011, courtesy of Dave Huth via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The United States And Ticks | Earth Wise

July 21, 2020 By EarthWise Leave a Comment

Tiny ticks are a big problem. Measuring only three to five millimeters in size, ticks are widely distributed around the world. They are external parasites, feasting on the blood of birds, reptiles, amphibians, and mammals – including humans.

According to estimates from the Centers for Disease Control and Prevention, ticks infect more than 300,000 people with Lyme disease in the United States every year, and the numbers continue to rise. Other common tick-borne diseases include anaplasmosis, babesiosis, Rocky Mountain Spotted Fever, and powassan encephalitis.

But while the prevalence of tick-borne illnesses has steadily increased in the United States over the past two decades, a new study on tick surveillance and control “has revealed an inconsistent and often under-supported patchwork of programs across the country.”

The study, by university researchers at the CDC’s five Vector-Borne Disease Regional Centers of Excellence, is the first-ever examination of tick management programs in the United States. The researchers found clear gaps in our public health infrastructure.

According to the study, which was recently published in the Journal of Medical Entomology, less than 50% of public health and vector-control agencies conduct tick surveillance. Only 25% test ticks for disease-causing germs. And only 12% conduct or support tick-control efforts. Researchers also discovered that the capacity for public tick-control efforts is low, as is the capacity for information and data sharing between agencies on ticks.

The findings highlight the degree to which tick surveillance and control is lagging in the United States. According to the research team, greater support for tick-management programs is critical, and they hope their findings will serve as a baseline from which to measure future improvements.

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Tick surveillance and control lagging in US

Photo, posted May 4, 2009, courtesy of Jerry Kirkhart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.