Formaldehyde is a colorless, flammable, strong-smelling chemical widely used to make home building products. Most formaldehyde produced in the United States is for the manufacture of resins, such as urea-formaldehyde, used to make the adhesives for pressed wood products, such as particleboard, furniture, paneling, cabinets, and other products.
Formaldehyde is also commonly used as a preservative in medical laboratories, mortuaries, and consumer products, including some hair smoothing and straightening products. It is also a by-product of automobile combustion and is produced in small amounts by most living organisms, including humans.
People are exposed to formaldehyde in the workplace and in their home environment, but the highest levels are found in work settings where formaldehyde is used or produced. Exposure to formaldehyde can occur in numerous industries and professions, such as manufacturers of formaldehyde and formaldehyde-based resins, woodworking, and furniture making. Morticians and laboratory workers may also be exposed to formaldehyde.
The general population is exposed to formaldehyde by breathing contaminated indoor or outdoor air and from tobacco smoke. Automobile and other combustion sources, such as woodstoves, incinerators, refineries, forest fires, and fumes released from new construction or home-finishing products, are some of the major sources of airborne formaldehyde.
Other consumer goods, including some hair smoothing and straightening products used in salons, cleaning agents, glues, and adhesives, may contain formaldehyde. Formaldehyde levels can be higher in indoor air than in outdoor air.
According to the report, several companies that use formaldehyde in their products, have been making efforts to remove or reformulate the chemical so it is less harmful.
Studies of workers exposed to high levels of formaldehyde, such as industrial workers and embalmers, found that formaldehyde causes myeloid leukemia, and rare cancers including sinonasal and nasopharyngeal cancer.
In laboratory animal studies, formaldehyde caused cancer primarily in the animal's nasal cavity.
The mechanisms by which formaldehyde causes cancer are not completely understood; however, formaldehyde clearly causes genetic damage in the nasal sinus of animals. Less is known about how it causes myeloid leukemia.
Lead is a naturally occurring metal found deep within the ground. It occurs in small amounts in ore, along with other elements such as silver, zinc or copper. Even though it's found in small amounts, there is an abundant supply of lead throughout the earth. Because it is widespread, easy to extract and easy to work with, lead has been used in a wide variety of products including:
Today, however, the most common sources of lead exposure in the United States are:
Lead can still be found in lead-based paint used in older homes, contaminated soil, household dust, drinking water pumped through leaded pipes, lead crystal, lead-glazed pottery, airplane fuel, some toys, and some inexpensive metal jewelry. Until 1978, lead paint was commonly used on the interior and exterior of homes.
Lead can get into your body in two ways — through breathing it in or by eating it. For example, lead can enter the body through eating or inhaling paint dust or chips. The soil around your home can pick up lead from sources such as exterior paint. Lead can also enter your drinking water through your plumbing.
No amount of lead is safe. Eliminating all lead exposure in our environment is our best course of action.
New findings from NIEHS-supported grantees, as well as NTP have found many adverse health effects in both children and adults at blood lead levels below 10 micrograms per deciliter (μg/dL) and for some below 5 μg/dL.
These findings add to the body of evidence that have led the Lead (CDC) in 2012 to now advise that any child with more than 5 micrograms per deciliter of lead in their blood to be considered at risk and that public health actions should be initiated.
Exposure to lead can have a wide range of effects on a child's development and behavior. Blood lead levels less than 10 micrograms per deciliter are associated with increased behavioral effects, delayed puberty, and decreases in hearing, cognitive performance, and postnatal growth or height.
Some of these health effects are found even at low blood lead levels less than 5 μg/dL, including lower IQ scores, decreased academic achievement, and increases in both behavioral problems and attention-related behaviors.
There is a wide range of lead-associated behavioral effects in the area of attention. Attention deficit hyperactivity disorder (ADHD) is one example on the more severe end of the spectrum.
Lead exposure has been linked to a number of health effects in adults. As a general rule, the more lead you have in your body, the more likely it is you’ll have health problems. High blood lead levels greater than 15 μg/dL are associated with cardiovascular effects, nerve disorders, decreased kidney function, and fertility problems, including delayed conception and adverse effects on sperm and semen, such as lower sperm counts and motility.
Blood lead levels below10 μg/dL are associated with decreased kidney function and increases in blood pressure, hypertension, and incidence of essential tremor, a degenerative disorder of the central nervous system whose most recognizable feature is a tremor of the arms or hands during voluntary movements, such as eating and writing.
There is also evidence showing that adults who have low levels of exposure to lead less than 5 μg/dL may have decreased kidney function. Pregnant women need to be particularly careful around lead. Maternal blood lead levels less than 5 μg/dL are associated with reduced fetal growth. Because the effects of lead are different for everyone, more research needs to be done to fully understand the health effects.
A study showed that lifetime lead exposure may increase the risk of developing cataracts,3 a clouding of the eye lens resulting in partial loss of vision, which can be common in older people.
Most adults with elevated blood lead levels are exposed to lead at work. Those in occupations related to mining, ironwork or welding, construction, renovation and remodeling activities, smelters, firing ranges, the manufacture and disposal of car batteries, automobile radiator repair, metal shop work, and the manufacture of pottery or stained glass are particularly at risk for lead exposure.
Yes, medications exist that can remove some lead from the body. However, no medical treatment is recommended for children with blood lead levels lower than 45 μg/dL. Medications, such as succimer, have been shown to significantly reduce lead in children with very high blood lead levels.
Although succimer lowered blood lead about 25% in the short term, it did not improve IQ or other test scores. This reinforces the need for prevention. Treatment after the fact does not undo the damage caused by lead. Children must be protected from being exposed at all.
Chronic lead exposure in adults can result in:
Children under the age of 6 years old are at an increased risk for lead exposure, due to their rapid rate of growth and their tendency to place toys and other objects in their mouths that could contain lead or leaded dust. This is particularly true of children living below the poverty line in older housing.
Ragweed and other weeds such as curly dock, lambs quarters, pigweed, plantain, sheep sorrel and sagebrush are some of the most prolific producers of pollen allergens.
Although the ragweed pollen season runs from August to November, ragweed pollen levels usually peak in mid-September in many areas in the country.
In addition, pollen counts are highest between 5:00 a.m. - 10:00 a.m. and on dry, hot and windy days.
As with tree pollen, grass pollen is regional as well as seasonal. In addition, grass pollen levels can be affected by temperature, time of day and rain.
Trees can aggravate your allergy whether or not they are on your property, since trees release large amounts of pollen that can be distributed miles away from the original source.
Most allergies are specific to one type of tree such as:
or to the male cultivar of certain trees. The female of these species are totally pollen-free:
Some people, though, do show cross-reactivity among trees in the alder, beech, birch and oak family, and the juniper and cedar family.
Molds are microscopic organisms that play an important role in the breakdown of plant and animal matter. Outdoors, molds can be found in shady, damp areas, or places where leaves or other vegetation is decomposing. Indoor molds can grow on virtually any surface, as long as moisture, oxygen, and organic material are present. When molds are disturbed, they release tiny cells called spores into the surrounding air.
People are exposed to molds every day and everywhere, at home, at work, at school, both indoors and out. Molds are generally not harmful to healthy humans.
Inhalation is considered the primary way that people are exposed to mold. Mold spores and fragments can become airborne and get into the air we breathe. People may also be exposed to mold through the skin. Workers should be properly protected with safety equipment when remediating, or cleaning up mold after a disaster. In some cases, people may be exposed to mold through their diet.
Symptoms stemming from mold spore exposure may include:
After contact with certain molds, individuals with chronic respiratory disease may have difficulty breathing, and people who are immunocompromised may be at increased risk for lung infection. A study conducted by NIEHS-funded scientists shows that mold exposure during the first year of life may increase the risk of childhood asthma.
To prevent fungus in your homes, or to get rid of it, you can do any of the following:
Dust mites are microscopic, insect-like pests that commonly live in house dust. They feed on flakes of dead skin, or dander, that are shed by people and pets. These tiny creatures are a big source of allergens and can worsen allergies and asthma. Dust mites can live in mattresses, bedding, upholstered furniture, carpets, curtains, and other places in your home.
Cockroaches are another source of indoor allergens. Researchers have found a link between the presence of cockroaches and an increase in the severity of asthma symptoms. These pests are most frequently found in urban areas and older dwellings.
The most effective way to prevent or minimize exposure to dust mites and cockroaches in your home is thorough cleaning, the use of high-efficiency particulate air (HEPA) filters, and pest management.
Traditional medications, such as antihistamines and inhaled steroids, may provide short-term control of allergy or asthma symptoms caused by dust mites or cockroaches. Immunotherapy, such as allergy shots and tablets, can change the body's immune response to allergens and may offer long-term control. People who suspect they are allergic to dust mites or cockroaches can see their doctor and get tested.
No matter how clean a home is, dust mites cannot be completely eliminated. However, the number of dust mites can be reduced by doing the following.
Dust mites are microscopic, insect-like pests that commonly live in house dust. They feed on flakes of dead skin, or dander, that are shed by people and pets. These tiny creatures are a big source of allergens and can worsen allergies and asthma. Dust mites can live in mattresses, bedding, upholstered furniture, carpets, curtains, and other places in your home.
Cockroaches are another source of indoor allergens. Researchers have found a link between the presence of cockroaches and an increase in the severity of asthma symptoms. These pests are most frequently found in urban areas and older dwellings.
The most effective way to prevent or minimize exposure to dust mites and cockroaches in your home is thorough cleaning, the use of high-efficiency particulate air (HEPA) filters, and pest management.
Traditional medications, such as antihistamines and inhaled steroids, may provide short-term control of allergy or asthma symptoms caused by dust mites or cockroaches. Immunotherapy, such as allergy shots and tablets, can change the body's immune response to allergens and may offer long-term control. People who suspect they are allergic to dust mites or cockroaches can see their doctor and get tested.
No matter how clean a home is, dust mites cannot be completely eliminated. However, the number of dust mites can be reduced by doing the following.
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 alter the global climate, which causes environmental changes to occur that can harm people's health and well-being.
While climate change is a global process, it has very local impacts that can profoundly affect communities. It can affect people's health and well-being in many ways, some of which are already occurring, by: