Category: Family Health

In December 2004, when a tsunami killed more than 200,000 people in 11 countries around the Indian Ocean, the United States was reminded of its own tsunami risks. In fact, devastating tsunamis have struck North America before and are sure to strike again. Especially vulnerable are the five Pacific States–Hawaii, Alaska, Washington, Oregon, and California–and the U.S. Caribbean islands…

Millions of workers are required to wear respirators in various workplaces throughout the United States. Respirators protect workers against insufficient oxygen environments, harmful dusts, fogs, smokes, mists, gases, vapors, and sprays. These hazards may cause cancer, lung impairment, diseases, or death. Compliance with the OSHA Respiratory Protection Standard could avert hundreds of deaths and thousands of illnesses annually.

Respirators protect the user in two basic ways. The first is by the removal of contaminants from the air. Respirators of this type include particulate respirators, which filter out airborne particles, and air-purifying respirators with cartridges/canisters which filter out chemicals and gases. Other respirators protect by supplying clean respirable air from another source. Respirators that fall into this category include airline respirators, which use compressed air from a remote source, and self-contained breathing apparatus (SCBA), which include their own air supply.

 

 

Decades of research have shown that air pollutants such as ozone and particulate matter (PM) increase the amount and seriousness of lung and heart disease and other health problems. More investigation is needed to further understand the role poor air quality plays in causing detrimental effects to health and increased disease, especially in vulnerable populations. Children, the elderly, and  people living in areas with high levels of air pollution are especially susceptible.

Results from these investigations are used to support the nation’s air quality standards under the Clean Air Act and contribute to improvements in public health.

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Health Effects of Air Pollutants on Vulnerable Populations

Research has shown that some people are more susceptible than others to air pollutants. These groups include children, pregnant women, older adults, and individuals with pre-existing heart and lung disease. People in low socioeconomic neighborhoods and communities may be more vulnerable to air pollution because of many factors. Proximity to industrial sources of air pollution, underlying health problems, poor nutrition, stress, and other factors can contribute to increased health impacts in these communities.

There is a need for greater understanding of the factors that may influence whether a population or age group is at increased risk of health effects from air pollution. In addition, advances to analytical approaches used to study the health effects from air pollution will improve exposure estimates for healthy and at-risk groups.

The research by EPA scientists and others inform the required reviews of the primary National Ambient Air Quality Standards (NAAQS), which is done with the development of Integrated Science Assessments (ISAs). These ISAs are mandated by Congress every five years to assess the current state of the science on criteria air pollutants and determine if the standards provide adequate protection to public health. 

Research is focused on addressing four areas:

• Identifying and characterizing whether there are key reproductive factors and critical stages of development that are impacted by air pollution exposures;
• Determining the role of acute and chronic sociodemographic factors in air pollution health disparities;
• Understanding how diet modifies responses to air pollution;
• Evaluating long-term lifestyle and chronic disease effects on air pollution-induced respiratory and cardiovascular responses

A multi-disciplinary team of investigators is coordinating epidemiological, human observational, and basic toxicological research to assess the effects of air pollution in at-risk populations and develop strategies to protect these populations, particularly those with pre-existing disease. The results from these products will improve risk assessments by clarifying the role of modifying factors such as psychosocial stress (e.g. noise) and diet, and determining the impact of individual susceptibility on the relationship between air pollutant exposures and health.

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Long-Term and Short-Term Effects from Exposure to Air Pollutants

People can experience exposure to varying concentrations of air pollution. Poor air quality can impact individuals for a short period of time during the day, or more frequently during a given day. Exposure to pollutants can also occur over multiple days, weeks or months due to seasonal air pollution, such as increased ozone during the summer or particulate matter from woodstoves during the winter.

The health impact of air pollution exposure depends on the duration and concentrations, and the health status of the affected populations. Studies are needed to increase knowledge of the exposure duration and the possible cumulative increase in risk.

The research is focused on three main areas: 

• Short-term peak exposures, such as wildfires, traffic-related sources, or other episodic events;
• Intermittent and cumulative exposures;
•  Mechanisms underlying the exposure risks

Researchers are evaluating the health responses of intermittent multiple days versus one-day air pollution exposure in controlled human exposure, animal, and in vitro models and associated cellular and molecular mechanisms. They are employing population-based models and electronic health records to assess the health effects of short-term and long-term exposures and identifying populations at greatest risk of health effects. The work is improving our understanding of the possible cumulative effects of multiple short-term peak exposures and the relationship of these exposures to longer-term exposures and risks.

Multipollutant Exposures and Changes in Environmental Conditions  

EPA research is providing information to understand how individuals may respond to two or more pollutants or mixtures and how environmental conditions may impact air quality. While risk estimates for exposure to individual criteria air pollutants such as PM and ozone are well established, the acute and cumulative effects of combinations of pollutants is not well understood. In addition, research is needed to determine how changes in the environment affect both pollutant formation and subsequent responsiveness to exposures in healthy and susceptible individuals.

The research is focused on three specific questions: 

• What is the role of temperature and photochemical aging on the health impact of wildfire smoke and air pollution mixtures?
• What is the effect of changing environmental conditions (i.e., temperature and humidity) on responsiveness to air pollution?
• Does prior pollutant exposure modify responsiveness to subsequent exposures?

The integrated, multi-disciplinary research includes:

• Epidemiologic analyses of environmental influences on morbidity and mortality in populations,
• Simulations of changing environmental conditions in multi-pollutant formation in atmospheric chamber studies coupled with clinical and toxicological assessments in healthy and at-risk populations,
• Evaluation of pre-exposure as a modifying effect on subsequent exposures

The results are revealing how changes in environmental conditions affect pollutant formation and subsequent health impact in at-risk populations. The research findings are informing EPA’s Integrated Science Assessments for criteria air pollutants and assisting with future regulatory decisions on the National Ambient Air Quality Standards (NAAQS).

Leveraging Big Data for Innovations in Health Science  

EPA is at the cutting edge of health science, using electronic health records, novel data systems, tissue-like advanced cellular models, molecular approaches, and animal models to evaluate the health impacts of air pollution.  Researchers are using these powerful new techniques to identify factors that may increase sensitivity and vulnerability to air pollution effects. 

The research is building capacity for future risk assessment and regulatory analyses that go beyond traditional lines of evidence to more clearly define populations and lifestages at increased risk of health effects from air pollution.

To continue to protect public health from poor air quality, researchers must consider new epidemiological, toxicological and clinical approaches to understand the health risks of poor air quality and the biological mechanisms responsible for these risks. At the center of these new research approaches is an explosion of data availability and methodological approaches for handling large clinical and molecular datasets, also known as “big data.”

While data of increasing size, depth, and complexity have accelerated research for many industries and scientific fields, big data is sometimes less recognized for the impacts it is having on environmental health studies. Increasingly, researchers are able to examine vulnerable populations with unprecedented precision and detail while also evaluating hundreds of thousands of molecular biomarkers in order to understand biological mechanisms associated with exposure.

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Health Effects of Wildfire Smoke

Larger and more intense wildfires are creating the potential for greater smoke production and chronic exposures in the United States, particularly in the West. Wildfires increase air pollution in surrounding areas and can affect regional air quality.

The health effects of wildfire smoke can range from eye and respiratory tract irritation to more serious disorders, including reduced lung function, exacerbation of asthma and heart failure, and premature death. Children, pregnant women, and the elderly are especially vulnerable to smoke exposure. Emissions from wildfires are known to cause increased visits to hospitals and clinics by those exposed to smoke.

It is important to more fully understand the human health effects associated with short- and long-term exposures to smoke from wildfires as well as prescribed fires, together referred to as wildland fires. EPA is conducting research to advance understanding of the health effects from different types of fires as well as combustion phases. Researchers want to know:

• What is the full extent of health effects from smoke exposure?
• Who is most at risk?
• Are there differences in health effects from different wildfire fuel types or combustion phases (burning versus flaming)?
• What strategies and approaches are most effective in protecting public health?
• What are the environmental, social and economic impacts of wildfire emissions?

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Public Health Intervention and Communications Strategies

Many communities throughout the United States face challenges in providing advice to residents about how best to protect their health when they are exposed to elevated concentrations of air pollutants from motor vehicle and industrial emissions and other sources of combustion, including wildland fire smoke.

Researchers are studying intervention strategies to reduce the health impacts from exposure to air pollution as well as ways to effectively communicate these health risks. To translate the science for use in public health communication and community empowerment, EPA is collaborating with other federal agencies, such as the Centers for Disease Control and Prevention (CDC) and the National Heart, Lung, and Blood Institute (NHLBI), and state and local agencies and tribes. The objectives are to identify ways to lower air pollution exposure or mitigate the biological responses at individual, community or ecosystem levels, and ultimately evaluate whether such interventions have benefits as measured by indicators of health, well-being or economics.

Studies are evaluating the interactions between behavior and social and economic factors to more thoroughly understand how these factors may influence health and well-being outcomes, which can inform effective and consistent health risk messaging. 

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Integrated Science Assessments for Air Pollutants

EPA sets National Ambient Air Quality Standards (NAAQS) for six principal criteria air pollutants—nitrogen oxides, sulfur oxides, particulate matter, carbon monoxide, ozone and lead—all of which have been shown to be harmful to public health and the environment.

The Agency’s Integrated Science Assessments (ISAs) form the scientific foundation for the review of the NAAQS standards by providing the primary (human health-based) assessments and secondary (welfare-based, e.g. ecology, visibility, materials) assessments. The ISAs are assessments of the state of the science on the criteria pollutants. They are conducted as mandated under the Clean Air Act.

Heart attacks occurring “out of the blue” may be rarer than some people have thought. A major new study suggests that nearly everyone who experiences a first-time heart attack, heart failure, or stroke has at least one of four factors that put them at increased risk for these conditions: less-than-optimal blood pressure, high cholesterol, elevated blood sugar, or being a current or former smoker.

The study, published Sept. 29, 2025, in the Journal of the American College of Cardiology, included more than nine million adults in Korea and nearly 7,000 in the United States. All had repeated health screenings and were followed for up to two decades. More than 99% of people who developed new coronary artery disease, heart failure, or stroke had at least one of the risk factors before their diagnosis. High blood pressure was the most common, affecting more than 95% of the Koreans and 93% of the Americans with new diagnoses.

Image: © Jacob Wackerhausen/Getty Images

For more than half a century, drugs known as beta blockers have been a mainstay for managing heart disease, especially for heart attack survivors. But doctors are now reconsidering that strategy, based on growing evidence showing that for some people who have had a heart attack, beta blockers might not offer any meaningful benefit. “For people whose hearts still pump normally after a heart attack, doctors may now think twice about prescribing a beta blocker,” says Dr. Cian McCarthy, a cardiologist at Harvard-affiliated Massachusetts General Hospital.

Sometimes, however, a heart attack leaves the left ventricle (the heart’s main pumping chamber) unable to contract effectively. When that’s the case, beta blockers are still recommended, he says. These drugs are also prescribed to treat angina (chest pain caused by narrowed heart arteries), to treat heart failure, to suppress abnormal heart rhythms such as atrial fibrillation, and to treat high blood pressure.

What are beta blockers?

You can identify beta blockers by their generic names — they all end in “lol.” Common examples include

• atenolol (Tenormin)
• bisoprolol
• carvedilol (Coreg)
• metoprolol (Lopressor, Toprol)
• nadolol
• propranolol (Inderal, InnoPran).

How do beta blockers work in the body?

Beta blockers work by blocking beta receptors, which are tiny proteins on the outer surfaces of cells throughout the body — notably in the heart, blood vessel walls, lungs, kidneys, and brain. Stress hormones (namely, epinephrine and norepinephrine) stimulate beta receptors, triggering effects that vary depending on the organ. In the heart and blood vessels, epinephrine and norepinephrine speed up the heart, strengthen the heart’s contractions, and tighten blood vessel walls.

Beta blockers subvert those effects by settling onto beta receptors and preventing the stress hormones from binding to them. As a result, the heart slows down and the blood vessels relax, actions that lower blood pressure and reduce the heart’s workload.

Common side effects of beta blockers

Beta blockers’ side effects are usually not life-threatening. But because beta receptors are found in so many different tissues, these drugs can have unwanted effects throughout the body, such as

• drowsiness or fatigue
• dizziness or lightheadedness
• cold hands and feet
• constipation
• erectile dysfunction.

Less common side effects include allergic reactions (such as rashes and swelling of the face) and trouble sleeping. If you have side effects from a beta blocker, talk to your doctor.

Beta blockers after a heart attack

A recent study examined the role of beta blockers in more than 8,500 heart attack survivors with normal or slightly impaired heart function. Half were randomly assigned to start taking a beta blocker within two weeks of leaving the hospital; the others did not take beta blockers. Over the following four years, researchers found no difference in repeat heart attacks, hospitalizations for heart failure, or death from any cause between the two groups. Published Aug. 30, 2025, in The New England Journal of Medicine, the findings apply to people with heart function that’s normal or only mildly reduced, defined as an ejection fraction of 40% or greater. The ejection fraction refers to the percentage of the blood that the heart sends out to the rest of the body each time it contracts. An ejection fraction of 50% to 70% is considered normal.

Who should — and shouldn’t — take beta blockers?

If you’ve had a heart attack and have what’s called a reduced ejection fraction (an ejection fraction below 40%), a beta blocker still makes sense. People with mildly reduced ejection fraction (40% to 49%) also likely benefit from beta blockers. But if you have a preserved ejection fraction (40% or higher), a beta blocker may not be needed. What if you have a preserved ejection fraction and are already on a beta blocker? “It may be reasonable to stop taking it one year after your heart attack, provided you don’t need the drug for another reason,” says Dr. McCarthy.

Beta blockers are generally less effective than other blood pressure drugs for preventing cardiovascular problems, especially strokes. “But while beta blockers aren’t a first-line choice, they can still be a useful addition if your blood pressure remains uncontrolled while you’re on other drugs,” Dr. McCarthy says.

Beta blockers are also used to prevent migraine attacks and decrease hand tremors. They can dampen common symptoms of anxiety such as sweating, rapid heartbeat, and blushing. Beta blocker eye drops are routinely prescribed to lower eye pressure in people with glaucoma. If you’re currently taking a beta blocker for any reason, don’t stop taking it before talking to your doctor.

This article appears in the January 2026 issue of Harvard Heart Letter under the title “New thinking on beta blocker use.”

Image: © LittleBee80/Getty Images

What is the Isabel Symptom Checker?

The Isabel Symptom Checker is a highly sophisticated medical knowledge system adapted from the professional Isabel Diagnosis Checklist System. Its job is to take a set of symptoms and present back a list of possible diagnoses that could be the cause of those symptoms. Each diagnosis is linked to knowledge to help you read up on the disease and learn more about it. The intention is not that you should bypass the doctor and diagnose yourself but to become more informed and be able to have a more balanced and productive discussion with your doctor or healthcare provider about your diagnosis.

When Should Isabel Be Used?

Isabel should be used when you have doubt about the diagnosis that your doctor has made about you. Everybody will have a different threshold before they have doubt but a good rule of thumb is that your doubt and concern should be based on the number of symptoms you have and how long you have had them. If you have had just one mild symptom for 2 days then it is far less likely to be anything serious than if you have had 2-3 symptoms lasting for 3-4 weeks, for example. You are the person who knows most about your symptoms, such as how long you have had them, how painful they are and whether they are getting worse or better so, if you feel concerned that you are not being listened to by your doctor, then that is a perfect time to use Isabel.

The Isabel Symptom Checker allows you to enter a list of symptoms and view possible associated diagnoses.

People with spinal cord injury (SCI) often need help with tasks of daily living. These include dressing, grooming, personal hygiene, and eating. They also include home management tasks, such as cooking, paying bills, and cleaning. A caregiver or personal assistant can provide that help. In some cases, a family member can fill this role. But in many cases, the caregiver is a paid employee. This sheet gives you more information about hiring a caregiver or personal assistant.

The best caregiver is someone you feel comfortable with.