Biomonitoring means measuring the levels of chemical substances in the human body that are hazardous to health and their metabolites. Employees need to be protected from hazardous chemicals that they may be exposed to in the work environment. Occupational health uses biomonitoring to measure the levels of chemical substances and their metabolites in the body.
According to the Regulation No. 105 “Occupational Health and Safety Requirements for the Use of Hazardous Chemicals and Materials Containing Them and Limit Values for Chemical Hazards in the Work Environment”, the employer shall ensure that employees whose health may be affected by hazardous chemicals undergo appropriate health surveillance and biological monitoring. Biomonitoring determines the level of a chemical or its metabolite in a worker’s blood or urine.
The employer has an obligation to create working conditions that are safe for the employee’s health and to implement necessary protective measures.  Despite the company’s efforts, measurements of the working environment and personal protective equipment, it is not always possible to be sure that the employee’s health is protected. Respirators, masks, protective clothing and ventilation may not be sufficient to prevent exposure to the hazardous substance. For this purpose, biological monitoring is used in occupational health to assess the level of chemical substances in the body on the basis of blood and urine tests and to ensure the safety of work processes.
For various substances, research has defined safe levels in the body. There are also various chemical elements in the environment, food, air and water around us. To a certain extent, they are not dangerous to human health because we have evolved to live in the environment around us. Exceeding a certain level or limit can have serious consequences for a persons health. Foremost, biomonitoring is needed to ensure that the protection measures already in place are adequate. In work processes where different chemical substances are used, protective measures are taken to increase the safety of the environment for the health of the employee. Such measures include ventilation, clothing, masks, respirators, goggles and other personal protective equipment. It is not always possible to be sure that they are sufficient to protect employees from the harmful effects of hazardous substances. If necessary, the employer must, in accordance with the law, arrange for the biomonitoring of employees, in the course of which the content of the chemical or its metabolite in the blood or urine is determined. Employees are exposed to various heavy metals in the work environment, which can be neurotoxic and damage the nervous system or carcinogenic and cause cancerous illnesses. Examples of metals that are hazardous are: lead, aluminum, manganese, chromium, nickel, cobalt, cadmium, mercury, iron, molybdenum, selenium, barium and semi-metallic arsenic. These heavy metals can be biomonitored from blood or urine. In the case of need and interest, contact Medihub biomonitoring specialists HERE. Medihub is in a close cooperation with the Finnish Institute of Occupational Health.
In Estonia, occupational health and safety requirements for the use of lead and its ionic compounds have been determined by a regulation.  Pursuant to § 4 (1) of the Regulation, biological monitoring must be carried out at least once every six months. Biological monitoring of lead may be carried out once a year if the level of lead in the air in the previous two measurements was 75-100 µg / m3 and the level of lead in the blood of no worker exceeds 50 Pg Pb / 100 ml. Medical examinations of employees exposed to lead or its ionic compounds must be carried out at least once a year. Particular attention should be paid in the health examination to the haematopoiesis, gastrointestinal tract, kidneys, peripheral and central nervous systems which may be affected by lead. The safe handling of chemicals is regulated by the Occupational Health and Safety Act and the Chemicals Act. In addition, the regulations set health and safety requirements for the use of hazardous chemicals and materials containing them  and for the handling of carcinogenic and mutagenic chemicals . Limits for chemical hazards in the work environment are set out in the Annex of the Regulation for the use of hazardous chemicals and materials containing them . It is important to understand that biomonitoring studies the levels of hazardous substances in the human body, not in the work environment. There are understandably different limits in the body (blood and urine) and in the work environment (air), i.e. readings that are considered dangerous to health. While the concentration of chemical substances in the environment can be assessed relatively well and limits have been set, the determination of concentrations in the human body is much more difficult.
Concentrations of chemicals and metabolites in body fluids (blood and urine) are often directly related to time passed from exposure and analysis techniques. For example, employee’s biological monitoring needs to know exactly when and for how long and during which activities they have been exposed to a hazardous chemical. The results of blood and urine tests (concentrations; limits) depend directly on this and uniform limits cannot be established until very precise agreement has been reached on how the tests will be taken and stored. For example, organic chemicals that are hazardous to employees’ health and their compounds, which should be biomonitored by the employer if necessary: isocyanates (foams, dyes, varnishes, adhesives), ethylene or styrene (watercraft, ABS thermoplastics), tetrachlorethylene or perchloroethylene (automotive chemicals) aromatic hydrocarbons or PAHs (building materials, bitumen, wood burning). In Estonia, biomonitoring of organic chemistry is possible by special order. If necessary and interested, contact Medihub biomonitoring specialists HERE. Medihub works closely with the Finnish Institute of Occupational Health.
In addition to classical biomonitoring (chemical hazards), measurements of the body’s reactions to organic dust (biological hazards) have been added in occupational health. For this purpose, the detection of antibodies against organic dust in the employee’s blood serum is used. Sometimes an increase in antibodies is associated with an allergic reaction, which is the body’s hyperreactivity to a particular compound or substance. If such an allergy is due to a risk factor in the work environment, it is counted as a work-related illness or occupational disease. Because human immune systems are different, as are responses to allergens, exposure limits for antibodies are not in one-to-one relation to the intensity of exposure to a risk factor in the work environment. Thus, the detection of antibodies is more indicative, e.g. direction giving research in biomonitoring.
 Translation of Work Health and Safety Act https://www.riigiteataja.ee/en/eli/528122021001/consolide
 Occupational health and safety requirements for the use of lead and its ionic compounds (in Estonian) https://www.riigiteataja.ee/akt/72095?leiaKehtiv
 Occupational health and safety requirements for the use of hazardous chemicals and materials containing them and limit values for chemical hazards in the work environment (in Estonian) https://www.riigiteataja.ee/akt/115052021004?leiaKehtiv
 Occupational health and safety requirements for the handling of carcinogenic and mutagenic chemicals (in Estonian) https://www.riigiteataja.ee/akt/117102019004?leiaKehtiv
 Limit values for chemical hazards (in Estonian) https://www.riigiteataja.ee/aktilisa/1150/5202/1004/VV_m105_lisa1_muudet.pdf#