Content Information
Acetaldehyde
CASRN 75-07-0
Physical Properties
Acetaldehyde (CH3CHO) is a colorless, flammable, volatile liquid or gas (above 69 degrees Fahrenheit) with a pungent, fruity odor detectable at low concentrations, between 0.05 and 2.3 parts per million (ppm).
Uses
Acetaldehyde is formed as a by-product of the fermentation process, the process that is used to make yeast and alcohol. It is also a by product of combustion (wood burning and motor vehicle use). Acetaldehyde is used in the synthesis of organic chemicals, resins, dyes, pesticides, disinfectants, cosmetics, gelatin, glue, lacquers, varnishes, casein products, explosives, and pharmaceuticals. It is also used as a hardener in photography, a flavoring agent, and as a leather preservative.
Source of Exposure in Iowa
Workers may be exposed to acetaldehyde in some manufacturing industries and during alcohol fermentation, where the principal route of exposure is most likely inhalation with possible dermal contact. Potential exposure also exists for people involved in the manufacturing or use of pesticides. Other sources of exposure are found in the manufacture of dyes, fabricated rubber, plastics, urea-formaldehyde foam insulation, lacquers, and varnishes. Acetaldehyde is a synthetic ingredient used in some processed foods.
Health Effects from Acute or Large Exposures
Exposure to acetaldehyde can occur through inhalation, ingestion, or contact with eyes, skin, or mucus membranes. Acute exposure to liquid acetaldehyde can irritate the eyes causing burning, watering, blurred vision, light sensitivity, and conjunctivitis. Breathing in vapors can also irritate the upper airways and cause burning pain and coughing. Exposure to high levels of acetaldehyde may cause headache, drowsiness, dizziness, excitement and agitation, followed by loss of consciousness, fluid filled lungs, and respiratory failure.
Health Effects from Smaller, Chronic Exposures
Repeated or prolonged contact with skin may cause dermatitis. Breathing acetaldehyde over time may have effects on the respiratory tract that result in tissue lesions. Acetaldehyde is reasonably anticipated to be a human carcinogen.
Protection from Exposure
Proper protective clothing and respiratory protection should be used by people exposed to larger amounts of acetaldehyde at the workplace. People exposed to large amounts of acetaldehyde should be moved to areas with fresh air as soon as possible.
Acrolein
CASRN 107-02-8
Physical Properties
Acrolein is a colorless or yellow liquid with a disagreeable, choking odor. It dissolves in water very easily and dissolves within some alcohols and other common organic solvents. Acrolein quickly changes to a vapor when heated. It ignites and burns easily in air.
Uses
The largest use for acrolein is as an intermediate chemical in the manufacture of other substances. Acrolein is also used as a herbicide and algaecide in drainage ditches and waterways, and as a biocide in the control of algae, weeds, and mollusks in recirculation process water systems.
Source of Exposure in Iowa
The most likely way you can be exposed to acrolein is by breathing air containing it. Individuals working within industries where acrolein is used in the manufacture of chemicals are the most likely people to be exposed to acrolein. Other individuals likely to receive the high exposures include smokers and those inhaling second-hand smoke, persons in close proximity to sources of wood and plastic smoke, including those in the forest products and firefighting communities, and populations living or working in areas of dense automotive traffic. Acrolein has not been found to be a contaminant in drinking water.
Health Effects from Acute or Large Exposures
Exposure to large amounts of acrolein can cause severe irritation to mucous membranes within the nose, throat, and lungs. Oral acrolein exposure may result in gastrointestinal discomfort, vomiting, and stomach ulceration and/or hemorrhage. Exposure to large amount of vapor or liquid on the skin may cause stinging of the eyes, and reddening, ulceration, or death of the skin tissue.
Health Effects from Smaller, Chronic Exposures
Exposure to smaller amounts of acrolein may cause your eyes to water and your nose and throat to become sore, but these effects disappear after exposure has stopped. Exposure to acrolein is not suspected to cause cancer. Protection from Exposure Proper safety equipment should be used when there is a potential to be exposed to large concentrations of acrolein in the workplace. Monitoring of acrolein levels in the air is needed to assure that levels are safe for people to work. Acrolein is a component of tobacco smoke. Avoid smoking in enclosed spaces like inside the home or car in order to limit exposure to children and other family members.
Aldrin, Dieldrin
CASRN 309-00-2 / 60-57-1
Physical Properties
Aldrin and dieldrin are insecticides with similar chemical structures. Pure aldrin and dieldrin are white powders with a mild chemical odor. The less pure commercial powders have a tan color. They bind tightly to soil and slowly evaporate into the air. They are discussed together in this fact sheet because aldrin quickly breaks down to dieldrin in the body and in the environment. Neither chemical occurs naturally in the environment.
Uses
From the 1950s until 1970, aldrin and dieldrin were widely used pesticides for crops like corn and cotton. Because of concerns about damage to the environment and potentially to human health, EPA banned all uses of aldrin and dieldrin in 1974, except to control termites. In 1987, EPA banned all uses of aldrin and dieldrin.
Source of Exposure in Iowa
Because of the persistent nature of these compounds, aldrin and dieldrin can still be found in the environment (in surface water, groundwater, soil, and sediment). Aldrin and dieldrin may also be found in landfills and hazardous waste sites. It is not known how much aldrin and dieldrin are presently stored in the United States. Since these chemicals were used as insecticides for corn production, it is possible that small amounts can still be found stored on farms. The EPA limits the amount of aldrin and dieldrin that may be present in drinking water to 0.001 and 0.002 milligrams per liter (mg/L) of water, respectively.
Health Effects from Acute or Large Exposures
People who have intentionally or accidentally ingested large amounts of aldrin or dieldrin suffered from mental excitation, seizures, and death. Renal (kidney) toxicity has also occurred from ingestion of large amounts of aldrin or dieldrin.
Health Effects from Smaller, Chronic Exposures
Health effects from chronic exposure may occur after a longer period of exposure to smaller amounts because these chemicals are stored in fat and leave the body slowly. Data from existing studies indicate that changes in the nervous system are the most likely effect of chronic exposure. Chronic animal studies additionally demonstrate adverse effects in the kidney and liver, with the liver being the most sensitive target organ. Conflicting evidence exists about the ability of aldrin or dieldrin to cause cancer in humans, and agencies are at odds in their classifications. The International Agency for Research on Cancer (IARC) has determined that aldrin and dieldrin are not classifiable as a human carcinogen. However, the EPA has determined that aldrin and dieldrin are probable human carcinogens.
Protection from Exposure
Since aldrin and dieldrin are no longer produced or used in the United States, exposure to these compounds should occur only from past usage. Because aldrin and dieldrin were applied to the basement of some homes for termite protection, before buying a home families should investigate what, if any, pesticides have been used within the home.
Ammonia
CASRN 7664-41-7
Physical Properties
Ammonia is a chemical that occurs naturally in the environment, and is man made. It is made up of one part nitrogen (N) and three parts hydrogen (H). Ammonia is a colorless gas with a sharp, pungent, suffocating odor. Ammonia in this form is also known as ammonia gas or anhydrous (“without water”) ammonia. Ammonia gas can be compressed, and becomes liquid under pressure. The odor of ammonia is familiar to most people, because ammonia is used in smelling salts, household cleaners, and window cleaning products. Ammonia easily dissolves in water. In this form, it is known as liquid ammonia, aqueous ammonia, or ammonia solution. Ammonia has an odor threshold of 25 to 50 parts per million (ppm) or 20 to 40 milligrams per cubic meter (mg/m3).
Uses
The most significant use of ammonia and ammonium compounds is the agricultural application of fertilizers. Ammonia and ammonium compounds used as fertilizer represent 89–90% of the commercially produced ammonia, with plastics, synthetic fibers and resins, explosives, and other uses accounting for most of the remainder. Ammonia is also used as a refrigerant in large commercial refrigeration units.
Source of Exposure in Iowa
People are most likely to be exposed to ammonia during agricultural activities. Anhydrous ammonia is used as a fertilizer, and is stored in large tanks at agricultural facilities and transported in smaller “nurse” tanks to be applied on crop land. Ammonia is also transported through large pipelines to agricultural facilities. Exposure to ammonia can result from leaks and spills related to its storage, transport and use. Ammonia is generated from the decay of organic matter and from livestock excreta. Exposure to ammonia can result from releases to the atmosphere and surface water from concentrated animal feeding operations (CAFOs).
Health Effects from Large Acute Exposures
Ammonia is a corrosive substance. Its main toxic effects are restricted to sites of direct contact (i.e., skin, eyes, respiratory tract, mouth, and digestive tract). Symptoms may range from coughing and watery eyes, to severe burns to the skin, eyes, throat, or lungs with large exposure. Severe burns may cause permanent blindness, lung disease, or death.
Health Effects from Smaller, Chronic Exposures
Long-term or chronic exposure to low levels of ammonia (less than 25 ppm) has not been shown to produce adverse health effects in workers exposed to ammonia. Some studies of farmers exposed to ammonia and other pollutants in livestock buildings indicated an association between exposure to pollutants, including ammonia, and increased respiratory symptoms (such as bronchial reactivity/hyper responsiveness, inflammation, cough, wheezing or shortness of breath) and/or a decrease in lung function. The contribution of ammonia to these respiratory symptoms is unclear. Ammonia has not been classified for carcinogenic effects.
Protection from Exposure
Proper safety equipment should be used when handling ammonia. Rubber gloves and chemical splash goggles should be worn. Ammonia's pungent odor and irritating properties usually provide adequate warning of its presence; however, olfactory fatigue can occur. Inhaling large amounts of ammonia can result in death. People should leave areas where the smell of ammonia is present. Cleaning chemicals containing ammonia should never be mixed with bleach, to prevent exposure to chlorine gas.
Arsenic
CASRN 7440-38-2
Physical Properties
Arsenic is an element widely distributed in the earth’s crust. Elemental arsenic is a steel grey metallic material that occurs naturally. However, in the environment, arsenic is usually combined with other elements, such as oxygen, chlorine, and sulfur. Arsenic combined with these elements is called inorganic arsenic. Arsenic combined with carbon and hydrogen is referred to as organic arsenic. Most inorganic and organic arsenic compounds are white or colorless powders that do not evaporate. They have no odor, and most have no taste; thus, it is difficult to tell if arsenic is present in food, water, or air.
Uses
About 90% of all arsenic produced is used as a preservative for wood, to make it resistant to rotting and decay. The preservative is called copper chromated arsenic (CCA), and the wood is referred to as “pressure-treated.” In 2003, U.S. manufacturers of wood preservatives containing arsenic began voluntary transition from CCA to other wood preservatives without arsenic in wood products for certain residential uses, such as play structures, picnic tables, decks, fencing, and boardwalks. This change was completed on December 31, 2003; however, wood treated with arsenic prior to this date may still be used, and existing structures made with CCA-treated wood prior to December 31, 2003 contain arsenic. Inorganic arsenic compounds have been used in pesticides in the past. Organic arsenic compounds are used in some pesticides. Small quantities of elemental arsenic are added to other metals to form mixtures or alloys with improved properties. Arsenic is most commonly use as an alloy in lead-acid batteries for automobiles. Another important use of arsenic compounds is in semiconductors and light-emitting diodes.
Source of Exposure in Iowa
Because arsenic occurs naturally in the environment, everyone is exposed to very low levels in air, water, and food. For most people, diet is the largest source of arsenic exposure. Arsenic concentrations may be substantially higher in certain seafood, although much of it is in the form of arsenobetaine, a relatively nontoxic organic compound. Arsenic is naturally present in Iowa soil and, in some areas, Iowa private water supplies may contain slightly elevated levels of arsenic. People who produce or use arsenic compounds in occupations such as nonferrous metal smelting, pesticide manufacturing or application, wood preservation, semiconductor manufacturing, or glass production may be exposed to substantially higher levels of arsenic, mainly from dusts or aerosols. One form of inorganic arsenic, arsenic trioxide was formed during the smelting of ore that contained arsenic, lead and copper. Arsenic and lead are no longer smelted in Iowa.
Health Effects from Large Acute Exposures
Arsenic had been recognized as human poison since ancient times. Doses larger than 60,000 parts per billion (ppb) in food or water can result in death. Smaller doses of inorganic arsenic (300 to 30,000 ppb in food or water) may cause irritation of the stomach and intestines, with symptoms such as stomachache, nausea, vomiting, and diarrhea. Other effects of ingesting inorganic arsenic include decreased production of red and white blood cells, causing fatigue, abnormal heart rhythm, blood vessel damage resulting in bruising, and impaired nerve function causing a "pins and needles" sensation in your hands and feet. Inhaling a large dose of inorganic arsenic may cause sore throat and irritated lungs.
Health Effects from Smaller Chronic Exposures
Perhaps the single-most characteristic effect of long-term oral exposure to inorganic arsenic is a pattern of skin changes. These include darkening of the skin and the appearance of small "corns" or "warts" on the palms, soles, and torso, often associated with changes in the blood vessels of the skin. A few corns may ultimately develop into skin cancer. Swallowing arsenic has also been reported to increase risk of liver, bladder, kidney, prostate, and lung cancer. Arsenic is classified as a known human carcinogen. Direct skin contact with inorganic arsenic compounds may cause irritation, redness and swelling. Skin contact does not appear to cause serious internal effects.
Protection from Exposure
All regulated public water supplies must be tested for the presence of arsenic. Some private wells may contain elevated levels; therefore, well water should be tested for arsenic. Reverse osmosis is the most reliable method for reducing arsenic levels in drinking water. To minimize the risk of exposure to arsenic from CCA-treated playsets, parents and caregivers should thoroughly wash a child’s hands with soap and water immediately after outdoor play, especially before eating. Children should be discouraged from eating on CCA-treated playgrounds.
Asbestos
CASRN 1332-21-4
Physical Properties
Asbestos is the name given to a group of six different fibrous minerals (amosite, chrysotile, crocidolite, and the fibrous varieties of tremolite, actinolite, and anthophyllite) that occur naturally in the environment. One of these, namely chrysotile, belongs to a serpentine family of minerals (flexible crystalline fibers), while all of the others belong to the amphibole family of minerals (more brittle fibers). Asbestos fibers can be smaller than the eye can see.
Uses
Asbestos minerals have separable long fibers that are strong and flexible enough to be spun and woven and are heat resistant. Because of these characteristics, asbestos has been used for a wide range of manufactured goods, mostly in building materials (roofing shingles, ceiling and floor tiles, paper products, and asbestos cement products), friction products (automobile clutch, brake, and transmission parts), heat-resistant fabrics, packaging, gaskets, and coatings. Previously asbestos fibers were used in spray insulation and fireproofing. This practice was prohibited by the Environmental Protection Agency in 1973.
Sources of Exposure in Iowa
People are exposed to low levels of asbestos by inhalation of fibers within air. Everyone is exposed to very small amounts of asbestos from natural sources (e.g., weathering of asbestos-containing minerals), and from deterioration of automobile clutches and brakes or breakdown of asbestos-containing (mainly chrysotile) materials, such as insulation. Tremolite asbestos is a contaminant in some vermiculite and talc. Higher exposure levels may result when asbestos is released from asbestos-containing building materials such as insulation, ceiling tiles, and floor tiles that are in poor condition or are disturbed. Workers involved in demolition work or asbestos abatement, as well as in building maintenance and repair, are potentially exposed to higher levels of asbestos.
Health Effects from Exposures
Workers who repeatedly breathe in asbestos fibers with lengths greater than or equal to 5 µm (micrometers) may develop a slow buildup of scar-like tissue in the lungs and in the membrane that surrounds the lungs. This scar-like tissue does not expand and contract like normal lung tissue and so breathing becomes difficult. Blood flow to the lung may also be decreased, and this causes the heart to enlarge. This disease is called asbestosis. People with asbestosis have shortness of breath, often accompanied by a cough. This is a serious disease and can eventually lead to disability or death in people exposed to high amounts of asbestos over a long period. However, asbestosis is not usually of concern to people exposed to low levels of asbestos. Changes in the membrane surrounding the lung, called pleural plaques, are quite common in people occupationally exposed to asbestos and are sometimes found in people living in areas with high environmental levels of asbestos.
People who are occupational exposed to asbestos have increased chances of getting two principal types of cancer: cancer of the lung tissue itself and mesothelioma, a cancer of the thin membrane that surrounds the lung and other internal organs. These diseases do not develop immediately following exposure to asbestos, but appear only after a number of years. There is also some evidence from studies of workers that breathing asbestos can increase the chances of getting cancer in other locations (for example, the stomach, intestines, esophagus, pancreas, and kidneys), but this is less certain. Members of the public who are exposed to lower levels of asbestos may also have increased chances of getting cancer, but the risks are usually small and are difficult to measure directly. Lung cancer is usually fatal, while mesothelioma is almost always fatal, often within a few months of diagnosis. Some scientists believe that early identification and intervention of mesothelioma may increase survival.
The levels of asbestos in air that lead to lung disease depend on several factors. The most important of these are:
- How long you were exposed,
- How long it has been since your exposure started, and
- Whether you smoked cigarettes. Cigarette smoking and asbestos exposure increase your chances of getting lung cancer.
Protection from Exposure
The most important way that families can lower their exposures to asbestos is to be aware of the sources of asbestos in their homes and avoid exposure to these sources. The most important source of asbestos in a home is from damaged or deteriorating asbestos-containing insulation, ceiling, or floor tiles. Should you suspect that your house may contain asbestos, contact the Iowa Department of Public Health, your local health department, or the Iowa Department of Natural Resources to find out how to test your home for asbestos and how to locate a company that is trained to remove or contain the asbestos fibers. Federal law requires schools to identify asbestos-containing material in school buildings and take appropriate action to control release of asbestos fibers. Appropriate respiratory protection should be worn by individuals occupationally exposed to asbestos.