Study found highest incidences of occupational carcinogenesis among clinical laboratory and histology technicians, followed by pathologists
It has been known for years that formalin (a form of formaldehyde used as a disinfectant and preservative in the handling of tissues samples in anatomy, pathology, and microbiology labs), as well as xylene and toluene, are dangerous to clinical laboratory workers. Nations around the world have taken steps to minimize exposure to these dangerous chemicals. However, a recent study in Iran found that those measures may not have gone far enough to protect histology and clinical laboratory technicians, pathologists, and medical laboratory scientists.
The study conducted by researchers in the Department of Occupational Health Engineering, School of Public Health, at Tehran University of Medical Sciences, showed that levels of exposure to these chemicals is still significantly higher than recommended, resulting in a higher risk for cancer among lab workers in Iran’s hospitals.
The scientists published their findings in the journal Nature Scientific Reports titled, “Occupational Exposure, Carcinogenic and Non-Carcinogenic Risk Assessment of Formaldehyde in the Pathology Labs of Hospitals in Iran.”
“Employing risk assessment techniques as a complementary tool in monitoring programs for respiratory exposure in the different work setting should be considered to protect the staffs against both non-cancerous and cancer-related hazards,” the study authors wrote.
Lessons learned from the Iranian hospital lab study could benefit clinical laboratory workers in US hospitals and help those who work with formaldehyde, toluene, and xylene worldwide to reduce their chances of developing a vascular condition known as Raynaud’s phenomenon (shown above) which can lead to necrosis and gangrene, as well as other dangerous health conditions affecting the lungs, brain, and other systems and organs in the body. (Photo copyright: Wikipedia.)
Study Details
The Iranian study considered the carcinogenic and non-carcinogenic impact of occupational exposure to formaldehyde in the pathology laboratories of four Tehran hospitals. The researchers “used a quantitative risk assessment method proposed by the United States Environmental Protection Agency (EPA), along with its provided database known as the Integrated Risk Information System (IRIS). Respiratory symptoms were assessed using the American Thoracic Society (ATS) questionnaire,” the study authors wrote in Nature Scientific Reports.
The scientists found that “91.23% of exposure levels in occupational groups exceed the NIOSH [National Institute for Occupational Safety and Health] standard of 0.016 ppm.” They determined that “41.03% of all the studied subjects were in the definite carcinogenic risk range (LCR > 10−4), 23.08% were in the possible carcinogenic risk range (10−5 < LCR < 10−4), and 35.90% were in the negligible risk range (LCR < 10−6),” they wrote.
“The highest index of occupational carcinogenesis was observed in the group of lab technicians with a risk number of 3.7 × 10-4, followed by pathologists with a risk number of 1.7 × 10-4,” the scientists wrote. “Furthermore, 23.08% of the studied subjects were within the permitted health risk range (HQ < 1.0), while 76.92% were within the unhealthy risk range (HQ > 1.0),” they added.
“Formaldehyde exhibits high solubility in water and is rapidly absorbed by the nasal cavity, sinuses, throat, and mucous membrane of the upper respiratory tract upon exposure,” the study authors wrote. “Consequently, due to the elevated potential for both carcinogenic and non-carcinogenic formaldehyde exposure among pathology staff—particularly laboratory technicians—the implementation of management measures … becomes imperative to lower the exposure levels of all employees below permissible limits.”
Those management measures include:
- “Strict guideline adherence and safe work protocols,
- “Increasing staff numbers to decrease exposure duration,
- “Adoption of engineering solutions such as localized ventilation systems, and
- “Use of respiratory protective equipment during sample handling and tissue processing.”
Previous Reports on Exposure Risk to Clinical Lab Workers
The knowledge of the danger behind these chemicals isn’t new.
In “National Academy of Sciences Confirms That Formaldehyde Can Cause Cancer in a Finding That Has Implications for Anatomic Pathology and Histology Laboratories,” Dark Daily covered how, in 2011, the US Department of Health and Human Services (HHS) National Toxicology Program’s (NTP) “Report on Carcinogens” was the first instance where formaldehyde was upgraded to “known to be a human carcinogen.”
In 2017, a pathology lab in Auckland, New Zealand, lost its accreditation because formaldehyde levels were so high the lab had to be evacuated nearly every day, The New Zealand Herald reported.
And in “Health of Pathology Laboratory Technicians at Risk from Common Solvents like Xylene and Toluene,” we reported on a 2011 study conducted in Wellington, New Zealand, that linked exposure to these chemicals with increased auto immune connective tissue diseases, notably doubling likelihood of developing Raynaud’s phenomenon.
“In epidemiological studies on industrial workers, pathologists and anatomists, the relationship between exposure to formaldehyde and an increased risk of various types of cancer including nasal cavity, nasopharynx, lung, brain, pancreas, prostate, colon and atopic lymphoma system has been determined,” the Iranian scientists wrote in Nature Scientific Reports.
Call for Stronger Regulations
“The Food and Drug Administration (FDA), the Consumer Product Safety Commission (CPSC), and the Environmental Protection Agency have expressed serious concern about the carcinogenicity of formaldehyde,” the Iranian scientists noted, adding that “the potential carcinogenic risk to humans has been studied in a number of cohort and case-control studies.”
There is room for more studies looking at the health effects of exposure to these chemicals among lab workers, as well as continued evaluation of the risks and preventative measures that could be taken. Perhaps tightened regulations will make its way to US labs, echoing more stringent ones of the European Union.
“It is imperative to implement control measures across various hospital departments to mitigate occupational formaldehyde exposure levels proactively. These findings can be valuable for policymakers in the health sector, aiding in the elimination or reduction of airborne formaldehyde exposure in work environments,” the Iranian scientists wrote.
Managers of histology and clinical laboratories may find useful advice in hospital laboratory studies like that coming out of Iran. Protecting the health of lab workers worldwide starts with reducing their exposure to deadly chemicals.
—Kristin Althea O’Connor
Related Information:
Pathology Lab Loses Accreditation Because of High Levels of Formaldehyde
Health of Pathology Laboratory Technicians at Risk from Common Solvents like Xylene and Toluene
