Heavy Metals Testing
Occupational health monitoring
Heavy metals are naturally occurring in our environment and our bodies contain certain levels of metals like zinc, needed for normal body function. However, health issues may occur when these metals present at abnormal or toxic levels.
Individuals working in occupational settings where heavy metals might be used for industrial processes, such as the mining industry, may be at higher risk of toxicity. Here, biological monitoring is an important tool to help safeguard employee health.
PathWest works closely with industry in Western Australia and nationally to provide biological monitoring for occupational exposure to harmful heavy metals, by supporting organisations to meet government guidelines and deliver occupational health and safety programs supporting employee health.
We have been providing heavy metals testing in Western Australia for over 30 years, offering targeted testing specific to local toxic metals. PathWest is the only laboratory in Western Australia to provide this specialised testing.
Using state-of-the-art technology, Inductive Coupled Plasma Mass Spectrometry (ICPMS), for analysis and offering a responsive service with fast turnaround times, PathWest works closely with industrial organisations and occupational health professionals to deliver an accurate, timely and specialised monitoring service.
Want to get a quote started for heavy metals testing? Get in touch with us.
How does heavy metals testing work?
Biological monitoring for exposure in a work environment is commonly used as a screening tool and is usually recommended where a risk assessment indicates that some employees may be exposed to concentrations of potentially harmful chemicals.
Exposure can be monitored by measuring the amount of heavy metals in either blood or urine. PathWest tests for the following:
- Urine - Arsenic (total and inorganic), mercury, cadmium, chromium, vanadium, iodine and cobalt
- Plasma - Aluminium, copper, zinc, selenium, manganese, and
- Blood - Lead.
We can also assist with screening for exposure to organophosphates pesticides or carbamate compounds (plasma and red cell cholinesterase).
Typically, heavy metals testing is used to:
- Screen for or to diagnose heavy metal poisoning in those who may have been acutely or chronically exposed to one or more heavy metals
- Guide management and treatment of heavy metal poisoning
- Monitor excessive metal concentrations in those who work with various heavy metals in occupations like in construction work, mining, radiator repair shops or firing ranges, and
- Monitor the effectiveness of chelation therapy, a treatment to rid the body of high amounts of a heavy metal.
Employee exposure is subject to regulation by various guidelines to monitor levels and ensure that an employee’s exposure remains below acceptable health standards.
Accreditations
PathWest is accredited by the National Association of Testing Authorities (NATA) to provide heavy metals testing.
Learn more about heavy metals testing
A heavy metals panel is a group of tests that detects and measures specific potentially toxic metals in the blood, urine or, more rarely, in the hair or other body tissue or fluid. A laboratory may offer several different heavy metals panels as well as individual tests for metals. The most common combination includes lead, mercury, arsenic and cadmium. Other panels may include one or more additional metals, such as cadmium, copper, or zinc.
Care must be taken in the interpretation of heavy metals tests. Your healthcare practitioner/doctor will interpret your results in the context of factors such as your risk of exposure, medical history, signs and symptoms and through a physical exam.
A low level of a heavy metal in the blood does not necessarily mean that excessive exposure has not occurred. Heavy metals do not stay in the blood and will not be present in the urine for extended periods of time. Lead, for instance, moves from the blood into the body's organs and over time is incorporated into the bones. If you were chronically exposed to lead, then you might have lead in your blood, urine, organs and bones.
Very low levels of many heavy metals may be present in the blood and urine of apparently healthy people because these metals are present throughout our environment. Recommendations for safe levels of heavy metals depend on your age and may change over time as more information about their safety becomes available.A baseline health surveillance is recommended prior to commencement of work, then at two and six months after the initial test.
Males and females (not of reproductive capacity)
| Blood Lead Level | Actions |
| 0 to 10 µg/dL | Test every six months |
| 10 to 20 µg/dL | Test every three months |
| >20 µg/dL | Test after six weeks |
| >30 µg/dL | Removal from exposure level |
Females of reproductive capacity
| Blood Lead Level | Actions |
| 0 to 5 µg/dL | Test every three months |
| 5 to 10 µg/dL | Test every six weeks |
| >20 µg/dL | Test after six weeks |
| >20 µg/dL | Removal from exposure level |
For mining operations (Mines Safety)
The employer submits the biological monitoring results to Mines Safety via Safety Regulation System.
For all other industries (WorkSafe)
The appointed medical practitioner (AMP) has a duty to notify health surveillance results to the regulator. The AMP forwards the completed Health Surveillance Notification Form Lead along with the pathology laboratory report to safety@dmirs.wa.gov.au.
In Western Australia, inorganic arsenic, arsenopyrite, is the most common occupational source of arsenic. It has been identified in the smelting of gold, nickel and tin where the ore contains arsenopyrite as an impurity.
Organic arsenic (mainly composed of arsenobetaine and arsenocholine), can be found in some foods and drinks like seafood, red wine and seaweed.
Arsenic from occupational sources occurs predominantly as As(III) and As(V). Both As(III) and As(V) are metabolised in the body and can be excreted in urine as the less toxic compounds, dimethyl arsenic acid (DMA) and monomethyl arsenic acid (MMA). In people exposed to high levels of As(III) or As(V) not all of the inorganic species will be converted in the body to MMA or DMA, and therefore As(III) and As(V) may also be excreted in urine. The total inorganic arsenic test result is the summation of MMA + DMA + As(III) + As(V).
PathWest offers biological monitoring of occupational exposure by measuring either ‘total’ or, more specifically, ‘inorganic arsenic plus methylated metabolites’ in urine. When spot-urine sample screening indicates total arsenic levels above 35 micrograms of total arsenic per litre of urine (35 μg As/L), reflex testing of the urine sample is conducted to specifically measure for inorganic arsenic plus its methylated metabolites.
More complex speciation analysis of urinary arsenic is available through special requests with the laboratory.
Metallic mercury is a silver-grey liquid that may be found as a contaminant or deleterious material in minerals mined in Western Australia. It is also found as cinnabar, a red-coloured mercury sulphide. Although mercury is generally not desired, some mineral processing methods concentrate mercury. Mercury may also be added in amalgamation processes to selectively bind minerals. It is a common contaminant in gold and silver refineries.
Inhaling mercury vapour is the main route of entry into the body, with as much as 80% absorbed into susceptible body tissues. Once absorbed, mercury is distributed throughout the body, with the majority accumulating in the kidneys and brain. Mercury has a biological half-life of about 60 days, with most being excreted in urine.
The major sources of non-occupational mercury exposure are inhalation of contaminated ambient air and ingestion of contaminated water or food. Dental amalgam has also contributed to very low levels of contamination in the general population. Bioaccumulation in contaminated marine populations such as shell-fish and fish are the most common source of dietary mercury poisoning. Organic mercury (e.g. methylmercury) is most commonly found in fish, and nearly all of it is absorbed by the body. Organic mercury is poorly excreted by the kidney but may cause elevated blood mercury levels.
Urine samples are generally used to estimate exposure to mercury vapour. The BEI for mercury is 35 micrograms of mercury per gram of creatinine (35μg Hg/g creatinine). Urine mercury levels are typically less than 10 μg Hg/g creatinine for people not occupationally exposed to mercury.
In Western Australian mining operations, lead is commonly found in fire assay laboratories and where lead nitrate or litharge is added during gold processing. Lead is also the principle commodity mined at several locations and is present as a contaminant or deleterious compound in many other ore deposits. Lead is present in significant quantities as a contaminant in the processing and smelting of mineral ores and hence, in mining wastes. Lead is used as an additive in fire assay laboratories and gold processing. Inorganic lead itself is mined as lead sulphide (galena) or lead carbonate resulting in exposures from mining, processing, transportation and storage.
Lead was historically used in fuel and paint, resulting in environmental contamination of soil. It is present in solder, metal alloys, radiators, old paintwork, detonators, explosives, bullets, batteries and lead shielding from radiation.
Lead-risk industries include lead soldering, radiator repair, lead alloys, fire assay laboratories, foundries (melting, casting, machining), lead battery manufacture or its breaking and dismantling, the welding, cutting or cleaning surfaces coated with lead or paint containing more than 1% lead, and its removal by abrasive blasting and high-pressure water jet or machining.
Non-occupational exposure can be significant from activities such as melting lead sinkers (fishing), home renovations, lead paint removal, use of cosmetics (kohl), lead glazed food containers and glassware.
Most forms of inorganic lead are readily absorbed and distributed throughout the body when inhaled or ingested. Absorption is strongly affected by nutritional status (iron and calcium deficiencies increase absorption).
Most lead stored in blood is attached to the haem molecule of red blood cells. The remaining portion of absorbed lead is contained in the bones, where the levels decrease very slowly, and the half-life is about 20 years
Occupational exposure to inorganic lead occurs in a wide range of industrial, manufacturing, construction and mining activities which produce lead dust or fumes.
Chromium (III) is a naturally-occurring element found in rocks, plants and soil. In urban areas, chromium is in the air from fossil fuel combustion. Chromium is an essential nutrient and foods high in chromium include green beans, broccoli and high bran breakfast cereals. The average adult ingestion is 50 to 200 μg/day.
Chromium exists in a series of oxidation states from 0 valence to 6+. The most important stable states are elemental metal (Cr0), trivalent (Cr3+) and hexavalent (Cr6+).
Examples of work activities involving inorganic chromium and its compounds which require special attention include:
- Welding, cutting and hard-facing of stainless steel
- Manual metal arc welding of high chromium steels
- Chrome plating
- Refractory production
- Addition of cement to gravel and sand to make concrete
- Leather tanning
- Timber preservation using, for example, copper chrome arsenic
- Chromate use in the textile industry, and
- Chrome pigment use, for example in paints.
The physician may also choose to monitor an employee’s exposure to chromium via urinary chromium level. Where urine analysis is carried out, the following values should be considered when assessing exposure to inorganic chromium:
Biological Occupational Exposure limit
Urine chromium <25 ug/L
Urine samples should be taken at the end of a work shift at the end of the work week.
Reference: ACGIH Biological Exposure IndicesMetal found in the earth’s crust, associated with zinc, lead, and copper ores. Cadmium is emitted to soil, water, and air by non-ferrous metal mining and refining, manufacture and application of phosphate fertilizers, fossil fuel combustion, and waste incineration and disposal. Tobacco leaves accumulate high levels of cadmium from the soil.
Highest risk of exposure from processes involving heating cadmium-containing materials such as smelting and electroplating. Risk will vary depending on the workplace. Major route of exposure is through inhalation of dust and fumes or incidental ingestion from contaminated hands, food, or cigarettes.
The measurement of cadmium in urine estimates chronic exposure. However, it may provide no information on exposure during the first year of exposure. The amount of cadmium in your blood shows your recent exposure to cadmium. In the workplace, the lungs are the major route of absorption of aerosols, dusts and fumes containing cadmium.
The main route of elimination of cadmium is renal. Renal tubular damage from cadmium or renal tubular dysfunction of other aetiologies results in increased renal elimination of cadmium.
Targets of cadmium toxicity are the kidney and bone following oral exposure and kidney and lung following inhalation exposure. The earliest indication of kidney damage in humans is an increased excretion of low molecular weight proteins, particularly β2-microglobulin and retinol binding protein.
Biological Occupational Exposure Limits
Spot urinary Cd/Cr <5 µg/g creatinine
Blood cadmium <5ug/L