* the potential for developing lung cancer as a result of exposure;

* the importance of avoiding skin contact;

* the engineering controls the employer is using to reduce worker exposures to beryllium;

* specific work practices that can be used to reduce exposure to beryllium;

* the use of appropriate protective equipment, including the use of respirators;

* the results of any industrial hygiene sampling for levels of beryllium in the workplace; and

* a copy of this Hazard Information Bulletin.

6. Health screening methods for beryllium sensitization and chronic beryllium disease

To the Employer:

Employers should consider sending beryllium-exposed employees to a physician or other licensed health care professional to be evaluated for beryllium sensitization or the presence of CBD. The screening examination for CBD usually begins with a chest x-ray and a blood test for beryllium sensitization, namely, the BeLPT, plus any further evaluation considered appropriate by the health care professional. The blood test can detect an adverse health response to beryllium exposure earlier than breathing tests or chest x-rays can. The BeLPT is not routinely done in most medical laboratories; however, the health care professional may order this test from any laboratory that has overnight courier service to one of the Medical Research Centers listed below. If a worker is sent to a health care professional for health screening, a copy of this Hazard Information Bulletin should accompany the employee.

To the Employee:

If you work in a place where beryllium is used and have developed any of the symptoms listed below, you should inform your health care professional of your past beryllium exposure, or seek information from a health care professional who specializes in occupational lung diseases to determine whether you may have developed CBD:

* unexplained cough,

* shortness of breath,

* fatigue,

* weight loss or loss of appetite,

* fevers, and/or

* skin rash.

If you do not have any of the above symptoms but are concerned that you may have become sensitized to beryllium, you should inform your health care professional that you would like to be tested with the blood BeLPT. Take a copy of this Hazard Information Bulletin with you.

Blood testing for beryllium sensitization

Only the three medical research centers and the one laboratory listed below currently offer the blood test to identify beryllium-sensitized workers as indicated by a positive blood BeLPT. As other research centers and laboratories develop the capacity to screen workers for beryllium sensitization, they will be added to the list.

Beryllium is a hard, grayish element that does not occur naturally. The element does occur as a chemical component of certain rocks, coal and oil, soil, and volcanic dust. Two kinds of mineral rocks, bertrandite and beryl, are mined commercially for the recovery of beryllium. Very pure gem-quality beryl is better known as either aquamarine (blue or blue-green) or emerald (green). Beryllium is also present in a variety of compounds. They do not have any particular smell. There are two types of beryllium compounds, those that dissolve in water and those that do not.

Most of the beryllium ore that is mined is converted into alloys (mixtures of metals). Most of these alloys are used in making electrical and electronic parts or as construction materials for machinery and molds for plastics. Pure beryllium metal has applications in nuclear weapons and reactors, aircraft and space vehicle structures and instruments, X-ray machines, and mirrors. Beryllium oxide is also made from beryllium ores and is used to make specialty ceramics for electrical and high-technology applications.

Fate

Beryllium enters the air, water, and soil as a result of natural and human activities. Emissions from burning coal and oil increase beryllium levels in air. Beryllium enters waterways from the wearing away of rocks and soil. Most of the man-made beryllium that enters waterways comes when industry dumps waste water and when beryllium dust in the air from industrial activities settles over water. Beryllium, as a chemical component, occurs naturally in soil; however, disposal of coal ash, incinerator ash, and industrial wastes may increase the concentration of beryllium in soil.

In air, beryllium compounds are present mostly as fine dust particles. The dust eventually settles over land and water. Rain and snow aid in the removal of beryllium from air. Sufficiently small beryllium particles may remain airborne for about 10 days.

Most of the beryllium in water settles in the material on the bottom. Beryllium compounds remain in ocean water for a few hundred years before settling to the bottom of the ocean. Fish do not accumulate beryllium from water into their bodies to any great extent. A major portion of beryllium in soil does not dissolve in water but remains bound to soil, so it is not very likely to move deeper into the ground and enter groundwater. In the environment, chemical reactions can change the water-soluble beryllium compounds into insoluble forms. In some cases, water-insoluble beryllium compounds can change to soluble forms. Exposure to water-soluble beryllium compounds in the environment, in general, will pose a greater threat to human health than water-insoluble forms.

Exposure Pathways

You can be exposed to low levels of beryllium by breathing air, eating food, or drinking water that contains beryllium. In the United States, the average concentration of beryllium in air is 0.03 nanograms (ng) (1 ng = 1 billionth of a gram) in a cubic meter (ng/m3) of air. In U.S. cities, the average air concentration is higher, and its value is 0.2 ng/m3 of air. Cities have higher levels of beryllium in the air because beryllium is released from burning coal and fuel oil. Beryllium was not found in 5% of 1,577 drinking water samples obtained throughout the United States. Of these samples, the average beryllium concentration was only 190 ng in a liter (L) of water. Beryllium, as a chemical component, is naturally found in some food. The concentration of beryllium in both raw carrots and field corn grown in the United States is less than 25 micrograms (ug) (1 ug = 1 millionth of a gram) in a kilogram (kg) of the fresh vegetables. The intake of beryllium for most people will be very small.

In certain workplaces you can be exposed to higher than normal levels of beryllium, mostly in the form of beryllium oxide and beryllium metal. Occupational exposure to beryllium occurs at places where the chemical is mined, processed, and converted into metal, alloys, and other chemicals. Workers engaged in machining metals containing beryllium, in recycling beryllium from scrap alloys, or in using beryllium products may also be exposed to higher levels of beryllium. An estimated 18,000 workers may be exposed to beryllium and beryllium oxide in the workplace.

As a member of the general public, you may be exposed to higher than normal levels of beryllium if you live near an industry that processes or uses beryllium. People who live near hazardous landfill sites that contain high concentrations of beryllium may also be exposed to higher than normal levels of beryllium. Beryllium, as a chemical component, occurs naturally in tobaccos and can be inhaled from cigarette smoke. People who smoke may breathe considerably more beryllium than people who do not smoke.

Beryllium metal and metal alloys may be found in consumer products such as electronic devices (e.g., televisions, calculators, and personal computers) and special nonsparking tools.

Metabolism

Beryllium can enter your body if you breathe air, eat food, or drink water containing it. Beryllium will not enter your body from skin contact with the metal unless the skin is scraped or cut and beryllium particles become imbedded in the wound. Only a small amount of beryllium may enter your body if your skin comes into contact with a beryllium salt dissolved in water. When you breathe air containing beryllium, beryllium particles can be deposited in the lungs. The beryllium that you breathe in slowly dissolves in the lungs and moves slowly into the bloodstream. Some of the beryllium deposited in the lungs can be moved to the mouth and then swallowed; the rest can remain in your lungs for a long time. If you eat food or drink water that contains beryllium, less than 1% passes from your stomach and intestines into the bloodstream. Therefore, most of the beryllium that you swallow leaves your body through the feces without entering the bloodstream. The small amount of beryllium that moves from the lungs, stomach, and intestines into the bloodstream is carried by the blood to the kidneys. Beryllium leaves the kidneys by the urine. Some beryllium can also be carried by the blood to the liver and bones where it may remain for long periods of time. If you swallow beryllium, beryllium leaves the body in a few days. However, if you inhale beryllium, it may take months to years before your body rids itself of beryllium. This is because it takes a long time before all the beryllium in the lungs enters the bloodstream or is swallowed.

Health Effects

Beryllium is a metal that can be harmful when you breathe it. The effects depend on how much and how long you are exposed to it. When you breathe it in, beryllium can damage your lungs. When you breathe in large amounts of soluble beryllium compounds, the lung damage resembles pneumonia with reddening and swelling of the lungs. This condition is called acute beryllium disease. In this case, if you stop breathing air with beryllium in it, the lung damage may heal. Some people can become sensitive to beryllium. This is known as hypersensitivity or allergy. If you become sensitive (allergic) to beryllium, you will develop an immune or inflammatory reaction to amounts of beryllium that do not cause effects in people who are not sensitive to beryllium. When this occurs, white cells accumulate around the beryllium and form a chronic inflammatory reaction called granulomas (granulomas are not tumors). This condition is called chronic beryllium disease. This disease can occur long after exposure to small amounts of either the soluble or the insoluble forms of beryllium. If you have this disease you may feel weak, tired, and have difficulty breathing.

Although the soluble and insoluble forms of beryllium can cause chronic beryllium disease, workers breathing air containing beryllium at less than 0.002 milligrams (mg) (1 mg = 1 thousandth of a gram of beryllium) in a cubic meter (mg/m3) (a level that government rules permit in the workplace) will probably not develop lung damage as a result of exposure. Both the short-term, pneumonia-like disease and the chronic beryllium disease can be fatal. Long periods of exposure to beryllium have been reported to cause cancer in laboratory animals, but some of these studies are not reliable. Some studies of workers reported an increased risk of lung cancer, but these studies are not conclusive, and new studies are being performed. The Department of Health and Human Services has determined that beryllium and certain beryllium compounds may reasonably be anticipated to be carcinogens. The International Agency for Research on Cancer has determined that beryllium and beryllium compounds are probably carcinogenic to humans. The EPA has determined that beryllium is a probable human carcinogen. We have no evidence that breathing air, eating food, or drinking water that contains beryllium or having skin contact with beryllium has any effects on reproduction or causes birth defects in humans or animals. Swallowing beryllium has not been reported to cause effects in humans because very little beryllium can move from the stomach and intestines into the bloodstream. Beryllium contact with skin that has been scraped or cut can cause rashes or ulcers. If you have developed an allergy to beryllium and have skin contact with it, you can get granulomas on the skin. These skin granulomas appear as a rash or as nodules. The skin granulomas are formed in the same way that lung granulomas are formed in sensitive people.

Information excerpted from

Toxicological Profile for Beryllium April 1993 Update Agency for Toxic Substances and Disease Registry United States Public Health Service

Synonyms BERYLLIUM-METALLIC; BERYLLIUM-9; GLUCINIUM; GLUCINUM; Beryllium-dust; Beryllium,-metal-powder

Analytical Methods 200.7 - 200.8 - 6010 - 6020

Molecular Formula Be

Synopsis

Beryllium - (Gr. beryllos.' beryl; also called Glucinium or Glucinum, Gr. glykys, sweet), Be; at. wt. 9.012182; at no. 4; m.p. 1287'C; b.p. 2471'C; sp. cyr. 1.948 (20'C): valence 2. Discovered as the oxide by Vauquelin in beryl and in emeralds in 1798. The metal was isolated in 1828 by Wobler and by Bussy independently by the action of potassium on beryllium chloride. Beryllium is found in some 30 mineral species, the most important of which are bertrandite, beryl, chrysoberyl, and phenacite. Aquamarine and emerald are precious forms of beryl. Beryl (3BeO - Al2O3-6SiO2) and bertrandite (4BeO - 2SiO2- H2O) are the most important commercial sources of the element and its compounds. Most of the metal is now prepared by reducing beryllium fluoride with magnesium metal. Beryllium metal did not become readily available to industry until 1957. The metal, steel gray in color, has many desirable properties. It is one of the lightest of all metals, and has one of the highest melting points of the light metals. Its modulus of elasticity is about one third greater than that of steel. It resists attack by concentrated nitric acid, has excellent thermal conductivity, and is nonmagnetic. It has a high permeability to X-rays, and when bombarded by alpha particles, as from radium or polonium, neutrons are produced in the ratio of about 30 neutrons/million alpha particles. At ordinary temperatures beryllium resists oxidation in air, although its ability to scratch glass is probably due to the formation of a thin layer of the oxide. Beryllium is used as an alloying agent in producing beryllium copper which is extensively used for springs, electrical contacts, spot-welding electrodes, and nonsparking tools. It has found application as a structural material for high-speed aircraft, missiles, spacecraft, and communication satellites. It is being used in the windshield , brake discs, support beams, and other structural components of the space shuttle. Because beryllium is relatively transparent to X-rays, ultra-thin Be-foil is finding use in X-ray lithography for reproduction of microminiature integrated circuits. Natural beryllium is made of 9Be and is stable. Eight other radioactive isotopes are known. Beryllium is used in nuclear reactors as a reflector or moderator for it has a low thermal neutron absorption cross section. It is used in gyroscopes, computerparts and instruments where flatness and stiffness, and dimensional stability are required. The oxide has a very high melting point and is also used in nuclear work and ceramic applications. Beryllium and its salts are toxic and should be handled with the greatest of care. Beryllium and its compounds should not be tasted to verify the sweetish nature of beryllium (as did early experimenters). The metal, its alloys, and its salts can be handled safely if certain work codes are observed, but no attempt should be made to work with beryllium before becoming familiar with proper safeguards. Beryllium metal is available at a cost of about $2.50/o, (99.5% pure).

Use SOURCE OF NEUTRONS WHEN BOMBARDED WITH ALPHA PARTICLES, YIELDS ABOUT 30 NEUTRONS PER MILLION ALPHA PARTICLES: HARDENING OF COPPER; MFR OF NONSPARKING ALLOY FOR TOOLS; MFR OF LIGHTWEIGHT ALLOYS /BERYL/ SPACE OPTICS, MISSILE FUEL AND SPACE VEHICLES X-RAY WINDOW COMPONENT OF ALLOYS-EG, WITH COPPER, NEUTRON MODERATOR IN NUCLEAR WEAPONS

Consumption Patterns FABRICATED PRODUCTS FROM ALLOYS

Apparent Color GRAY METAL, CLOSE-PACKED HEXAGONAL STRUCTURE; A GRAYISH-WHITE, HARD LIGHT METAL

Odor Odorless

Boiling Point 2970 Deg C

Melting Point 1287 DEG C

Molecular Weight 9.0121

Density 1.85 at 20 deg C

Sensitivity Data Soluble beryllium salts are directly irritating to skin and mucous membranes.

Chemical and

Physical Properties

HEAT CAPACITY AT CONSTANT PRESSURE: (30 DEG C) 0.437 CAL/G/DEG C; LATENT HEAT OF FUSION: 3.5 KCAL/MOL; BRINELL HARDNESS: 60-125; HAS HIGH PERMEABILITY TO X-RAYS; ANISOTROPIC; CHEMICAL PROPERTIES SIMILAR TO ALUMINUM; METAL RESISTANT TO ATTACK BY ACID DUE TO FORMATION OF A THIN OXIDE FILM. DUCTILITY IS SUFFICIENT AT 1000 DEG C TO PERMIT BERYLLIUM TO BE SWAGED; REACTS WITH OTHER ELEMENTS ONLY AT ELEVATED TEMPERATURES: AT 700 DEG C OXIDATION IS NOTICEABLE, AT 1000 DEG C, RAPID

Environmental Impact

The influence of aerosol suspension from clothing on personal monitor exposure estimates was investigated in a beryllium facility. Samples of 100% cotton and 100% Nomex fabrics used at the beryllium facility were tested. The deposition of airborne beryllium into fabrics was significantly enchanced by electrostatic attraction on cotton but not on Nomex fabrics. Both fabrics collected more beryllium in motion than on stationary units. Personal monitors mounted in front of fabrics collected more beryllium when the fabrics were agitated than when monitors were placed in the positions of the nose and mouth. The air concentrations increased as fabric load increased, but leveled off at high fabric load concentrations. Resuspension from cotton was higher than from Nomex. Ressupension of aerosol from garments can cause erroneously high exposure measurements from chest mounted personal monitors. Workshirts worn by employees at a beryllium refinery resuspended beryllium containing dust. The old shirts resuspended significantly higher quantities of beryllium to the air than did the washed and unwashed new shirts. A considerable fraction of the Be measured in air was respirable. Fourteen dental casting alloys were analyzed for release of nickel and beryllium into acidic salivary soln in vitro. Corrosion rates at varying pH levels and time in soln were calc over a 120 day period and the possible significance of these rates to allergic reactions or other health hazards were postulated. When the beryllium levels were analyzed for these alloys they were much higher than expected. In each of the alloys, since the nickel cmpd was often 66-78% of the cmpd and the beryllium level a max of 2%, the differences in magnitude of nickel vs beryllium concn might be expected to be on the order of 30/1 or greater. The differences were closer to 8/1. Nickel and beryllium containing dental casting alloys have the potential to be a significant hazard to the lab technician, dentist and patient.

Environmental Fate

ESTIMATES OF ABUNDANCE IN EARTH'S CRUST VARY FROM 2 TO 10 PPM. NATURAL ISOTOPES: 9 (100%); RADIOACTIVE ISOTOPES (MASS NUMBERS): 6-8; 10-12. FOUND IN PHENACITE, CHRYSOBERYL PRECIOUS FORMS OF BERYL: EMERALD, AQUAMARINE. Beryllium is concentrated in silicate minerals relative to sulfides. In common crystalline rocks, the element is enriched in the feldspar minerals relative to ferromagnesium minerals and apparently replace the silicon ion; 85-95% of the total crystal beryllium may be bound in the feldspar structures. The greatest known concentrations of beryllium are found in certain pegmatite bodies, where crystals of beryl account for a few percent of the total pegmatite volume, and may be found in several of the strata of zoned dykes. The element is sometimes concentrated in hydrothermal veins, and some granitic rocks contain sufficient amounts to permit the crystallization of small amounts of beryl. CERTAIN FOSSIL FUELS CONTAIN BERYLLIUM CMPD, ACCOUNTING FOR THE PRESENCE OF BERYLLIUM IN SOME COMMUNITY AIR SAMPLES AND TISSUES OF CITY RESIDENTS. Ceramic artists can be exposed to many hazardous materials, generally related to dry clays, glazes and kiln use. Glazes can contain lead, antimony, arsenic, barium, beryllium, boron, chromium, cobalt, cadmium, copper, vanadium and other materials which all have potential toxic effects. Beryllium enters the environment principally from coal combustion. Be contents in the ashes from a Czechoslovakian power plant were determined (coarse (> 20 mm) and fine (2.0 to 0.2 mm) fraction from dump, and fine (0.2 mm) fraction from electrostatic precipitators). Acidic and alkali aqueous extracts of these ashes contained various concentrations of Be (1 to 17% of total concentrations). Wastewater showned 3.15 and 3.4 ug Be/l. Thus, secondary long term beryllium pollution emerges from the slag and ash dumps. Soil concn generally range from 0.1-40 ppm, with the average around 6 ppm. Beryllium concentrations (dry weight) of 0.08 mg/kg in polished rice, 0.12 mg/kg in toasted bread, 0.17 mg/kg in potatoes, 0.24 mg/kg in tomatoes, and 0.33 mg/kg in head lettuce. Beryllium levels (ppm in ash) for different foodstuffs were: beans, 0.01; cabbage, 0.05; hen eggs (yolk) 0.01; milk, 0.02; mushrooms, 0.12; nuts, 0.01- 0.47; tomatos, 0.02; and baker's yeast, 0.02. In birch, aspen and willow beryllium content may rise as high as 3 mg/kg. Potatoes contain 0.17 mg/kg dry substance, tomatoes 0.24 mg/kg and head lettuce 0.33 mg/kg. Beryllium in root, stem, and leaf tissues of tobacco (Nicotiana tabacum L Md-609) plants grown in McMurtrey's nutrient solution with addition of 0.3, 1.0 and 3.0 mg/l Be were determined by gas chromatography-mass spectrometric analysis using m/l 246 of beryllium trifluoroacetylacetonate chelates. The method was sensitive to about 4 pg of Be. The majority of Be was associated with tobacco roots (0.3, 1.0 and 3.0 mg/l of Be were added to the solution were associated with 374, 427 and 4280 ug Be/g dry wt of tissue, respectively; leaves were associated with 2.14, 2.36 and 81.4 ug Be/g dry wt tissue respectively. ACCORDING TO STUDIES ON COWS WITH RADIOACTIVE BERYLLIUM, LESS THAN 0.002% OF INJECTED ACTIVITY WAS RECOVERED IN MILK. BIOLOGICAL HALF-LIFE IN MILK WAS 19 HR. Beryllium level reported in milk, 0.02 ppm in ash. FOOD NOT SIGNIFICANT SOURCE OF HUMAN EXPOSURE NO EVIDENCE THAT BERYLLIUM IS MOVING FROM SOILS INTO FOOD OR FEED PLANTS IN AMOUNTS DETRIMENTAL. Humans: total body burden: 36 ug Beryllium; 24 ug Beryllium in soft tissue. Humans: Kidney; 0.2 ug beryllium/kg: liver; 1.6 ug beryllium/kg: muscle; 0.75 ug beryllium/kg: bone; 3.0 ug beryllium/kg: hair; 6.0-20.0 ug beryllium/kg Human: blood: 0.01 ug beryllium/l Humans: lung: 1x10 2 to 1x10 5 ug beryllium/l: blood: 0.02-3.0 ug beryllium/l: urine: 0.02-3.0 ug beryllium. The soft tissue burden of an adult is likely to be less than 20 ug and the skeletal burden about 30 ug.

Drinking Water

Impact

The authors reported the results of trace metal analysis of 1,577 drinking water samples. Beryllium was detected in 5.4% of the samples and concentrations ranged from 0.01 to 1.22 mg/l with a mean value of 0.19 ug/l. Analysis of surface, ground, and rain waters have shown that beryllium concentrations are well below 1.0 ug/l. It was reported that the maximum beryllium concentration in 20 rain water samples and 56 river water samples (from 5 different Australian rivers) was 0.18 ug/l. Even heavily polluted Rhine and Main rivers in Germany, the concentrations were below 0.02 ug/l. EFFL: BASED ON ENRICHMENTS RELATIVE TO COAL AS A FUNCTION OF FLY ASH PARTICLE SIZE, BERYLLIUM BEHAVIOR WAS BETWEEN A) LITTLE OR NO ENRICHMENT IN THE SMALL PARTICLE FRACTION

Disposal

At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices. Beryllium (powder) waste should be converted into chemically inert oxides using incineration and particulate collection techniques. Recovery and recycle is an alternative to disposal for beryllium scrap and pickle liquors containing beryllium. PRECAUTIONS FOR "CARCINOGENS": There is no universal method of disposal that has been proved satisfactory for all carcinogenic compounds

Atmosphere

URBAN AIR METAL PARTICLE CONCENTRATION IN THE US 1964-1965. POLLUTANT BERYLLIUM; AVERAGE CONCN LESS THAN 0.0005 UG/CU M; MAX CONCN 0.010 UG/CU M. At a beryllium extraction plant in Ohio, concentrations were approximately 2 mg/cu m over a 7 year period. Beryllium was present in 12% of 440 air samples analyzed from 16 cities. Concentrations ranged from 0.001 to 0.002 ug/cu m in urban areas and 0.00013 ug/cu m in more rural areas.

Hazard Summary-Created in April 1992; Revised in January 2000

Inhalation exposure to beryllium primarily occurs in the workplaces where it is mined, processed, or converted into alloys and chemicals, or from the burning of coal or fuel oil and in tobacco smoke. Acute (short-term) inhalation exposure to high levels of beryllium has been observed to cause inflammation of the lungs or acute pneumonitis (reddening and swelling of the lungs) in humans; after exposure ends, these symptoms may be reversible. Chronic (long-term) inhalation exposure of humans to beryllium has been reported to cause chronic beryllium disease (berylliosis), in which granulomatous lesions (noncancerous) develop in the lung. Human epidemiology studies are limited, but suggest a causal relationship between beryllium exposure and an increased risk of lung cancer. Inhalation exposure to beryllium has been demonstrated to cause lung cancer in rats and monkeys. EPA has classified beryllium as a Group B1, probable human carcinogen.

Is this your not-so-evil twin?

Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS), which contains information on oral chronic toxicity and the RfD and inhalation chronic toxicity and the RfC, and the carcinogenic effects of beryllium including the unit cancer risk for inhalation exposure, EPA's Toxicological Review of Beryllium and Compounds, and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Beryllium.

Uses

* Pure beryllium and its metal alloys have applications in electrical components, tools, structural components for aircraft, missiles, and satellites, and other metal-fabricating uses. (1)

* Beryllium is also used in consumer products, such as televisions, calculators, and personal computers. (1)

Sources and Potential Exposure

* The greatest exposures to beryllium occur in the workplace (i.e., where it is mined, processed, or converted into alloys and chemicals). (1)

* Individuals may also be exposed by inhalation of beryllium dust or fumes from the burning of coal or fuel oil and in tobacco smoke, by the ingestion of many fruits and vegetables and water, or through natural occurrence in soils. (1)

* The average concentration of beryllium measured in the air in the United States during the 1980s was 0.03 nanograms per cubic meter (ng/m3). Ambient concentrations measured in 50 cities between 1977 and 1981 were 0.1-0.4 ng/m3. (1)

Assessing Personal Exposure

* Beryllium levels can be measured in urine and blood, but the levels in urine are quite variable, making it difficult to use these levels to assess total exposure. (1)