The NIEHS provides information about chemicals or environmental factors that humans are exposed to that may cause adverse health effects.
Acrylamide is a chemical widely used in the manufacturing of paper, dyes, and other industrial products. It can also form when certain foods are cooked at high temperatures.
Air pollution is a well-known environmental health hazard. We know what we’re up against when a brown haze settles over a city, exhaust fumes billow on a busy highway, or a plume rises from a chimney. Some air pollution is not visible, but its pungent smell alerts you.
Algae is always found in natural bodies of water like oceans, lakes and rivers, and a few types produce toxins. A harmful algal bloom (HAB) occurs when toxin-producing algae grow excessively in a body of water.
Information on allergens, asthma, and lung research conducted at NIEHS | Additional Resources for Managing Allergies
Aloe is a succulent plant widely used in alternative medicine. There are at least 420 different plant species of Aloe. Aloe vera specifically refers to the Aloe barbadensis Miller plant, which is the most commonly used form in Aloe products.
Arsenic is a natural element widely distributed in the earth’s crust. It is found in water, air, food and soil. Exposure to arsenic affects human health.
Bisphenol A (BPA) is a widely produced chemical primarily used in the production of polycarbonate plastics and epoxy resins. NIEHS and NTP support research to better understand the potential health effects of BPA exposure.
The National Toxicology Program, headquartered at NIEHS, has conducted studies to help us understand the potential health risks, including cancer risk, from exposure to radio frequency radiation such as that used in 2G and 3G cell phones.
Climate change is the result of the buildup of greenhouse gases in the atmosphere, primarily from the burning of fossil fuels for energy and other human activities. These gases, such as carbon dioxide and methane, warm and change the global climate, causing environmental changes that can harm people’s health and well-being.
Cosmetics and personal care products contain a mixture of chemicals. Researchers are working to better understand whether these substances affect human health. Some chemicals are classified as endocrine disruptors, meaning they can interfere with the body’s hormones and cause adverse health effects.
Dioxins are primarily byproducts of industrial practices. They are produced by various incineration processes, including improper incineration of municipal waste and waste burning, and can be released into the air during natural processes, such as forest fires and volcanoes. Almost all living creatures have been exposed to dioxins or dioxin-like compounds (DLCs).
Dust mites are microscopic insect-like parasites that typically live in house dust. They feed on flakes of dead skin, or dander, shed by humans and pets. Cockroaches are another source of indoor allergens. Researchers have discovered a link between the presence of cockroaches and an increase in the severity of asthma symptoms.
Electric and magnetic fields (EMFs) are invisible areas of energy, often called radiation, associated with the use of electrical energy and various forms of natural and artificial lighting. Learn the difference between ionizing and non-ionizing radiation, the electromagnetic spectrum, and how EMF can affect your health.
Endocrine disruptors are natural or artificial chemicals that can mimic or interfere with the body’s hormones, called the endocrine system. These chemicals are linked to many health problems, both in wildlife and humans.
Essential oils are concentrated plant extracts that retain the natural scent and flavor of their source. Some essential oils and their components exhibit hormonal activity and could affect the endocrine system.
Flame retardants are chemicals applied to materials to prevent the start or slow the growth of a fire. Some of these chemicals are associated with adverse health effects in animals and humans.
Formaldehyde is a colorless, flammable, strong-odor chemical widely used in the manufacture of residential building products. Most formaldehyde produced in the United States goes to making resins, such as urea-formaldehyde, used to make adhesives for pressed wood products, such as particleboard, furniture, panels , cabinets and other products.
Hazardous waste is discarded material whose properties make it potentially harmful to human health or the environment.
Hexavalent chromium is a form of the metallic element chromium. Chromium is a natural element found in rocks, animals, plants, soil, and volcanic dust and gases. It comes in several different forms, including trivalent chromium and hexavalent chromium.
Hydraulic fracturing, or fracking, is a method used to extract natural gas and oil from deep rock formations known as shale. Using this method, drilling operators force water, sand and a mixture of chemicals into horizontally drilled wells, causing the shale to crack and release natural gas or oil.
We tend to think of air pollution as a risk we face outdoors, but the air we breathe indoors can also be polluted.
Lead, a metal found everywhere on earth, has been used in a variety of products, including gasoline, paint, plumbing pipes, ceramics, solder, batteries and even cosmetics. This remains a significant public health concern for some children due to ongoing risks from lead in the environment.
Mercury is a metal that is toxic to living organisms. It exists in several forms, some of which occur naturally in the environment. Metallic or elemental mercury – an odorless, shiny, silvery-white liquid – is commonly used in thermometers, barometers and fluorescent light bulbs. Metallic mercury is extremely dangerous: a few drops generate enough fumes to contaminate the air in a room. Additionally, skin contact with the metal leads to absorption of mercury into the bloodstream and potential health problems.
A micro-organism and type of fungus, mold is part of the natural environment and is found everywhere, outdoors and indoors. Health-related reactions in people depend on the type of mold, the amount and duration of exposure, and individual characteristics.
Nanomaterials, natural and man-made, are characterized by their size, measured in nanometers. A nanometer is one millionth of a millimeter, or about 100,000 times smaller than the diameter of a single hair. NIEHS is working to understand the potential risks associated with exposure to these materials.
Per- and polyfluoroalkyl substances (PFAS) are a large and complex group of synthetic chemicals used in consumer products around the world since around the 1950s. They are used in the composition of various everyday products. For example, PFAS are used to prevent food from sticking to packaging or cooking utensils, make clothing and carpets stain-resistant, and create more effective firefighting foam. PFAS molecules have a chain of linked carbon and fluorine atoms. Since the carbon-fluorine bond is one of the strongest, these chemicals do not break down easily in the environment.
A pesticide is any substance used to kill, repel or control certain forms of plant or animal life considered harmful. Pesticides include herbicides to destroy weeds and other unwanted vegetation, insecticides to control a wide variety of insects, fungicides used to prevent the growth of mold, disinfectants to prevent the spread of bacteria, and compounds used to fight against mice and rats.
Millions of Americans live with pets even if they are allergic to them. Any furry animal can trigger allergy symptoms like sneezing or red, itchy eyes, but most commonly cats and dogs. Animal allergies can also make asthma harder to control.
For a tree or flowering plant, pollen is necessary for life. But for millions of Americans, it is a source of seasonal misery. Pollen, a fine to coarse powdery substance, is created by certain plants as part of their reproductive process. It can appear on trees in spring, on grasses in summer, and on weeds in fall.
Radon is a natural, colorless and odorless radioactive gas. Radon comes from the natural decay of uranium or thorium, elements present in rocks, soil and water. Radon breaks down quickly and releases radioactive particles. When inhaled, these radioactive particles can damage the cells lining the lungs.
Water is essential for life. People depend on clean water for their health and livelihoods. But contaminated water causes millions of deaths and even more illnesses every year.
The link between cigarette smoke and diseases, including lung cancer and cardiovascular disease, is well known. Tobacco use is the leading cause of preventable death in the United States.
Styrene is a colorless, flammable liquid that has a sweet odor and is very volatile. Styrene is widely used to make plastics and rubber, which are used in the manufacture of various products, such as insulation, pipes, automobile parts, printing cartridges, food containers and carpet backing.
Extreme weather events can have adverse effects on human health, particularly due to severe heat and cold. Storms and harsh conditions, such as hurricanes and droughts, can create secondary hazards, including flooding and wildfires. The NIEHS has resources on many types of events and conditions.
