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.
“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 NatureScientific 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 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.
“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.
As standard masks are used they collect exhaled airborne pathogens that remain living in the masks’ fibers, rendering them infectious when handled
Surgical-style facial masks harbor a secret—viruses that could be infectious to the people wearing them. However, masks can become effective virus killers as well. At least that’s what researchers at the University of Alberta (UAlberta) in Edmonton, Canada, have concluded.
If true, such a re-engineered mask could protect clinical laboratory workers from exposure to infectious diseases, such as, SARS (Severe Acute Respiratory Syndrome), MERS (Middle East Respiratory Syndrome), and Swine Influenza.
“Surgical masks were originally designed to protect the wearer from infectious droplets in clinical settings, but it doesn’t help much to prevent the spread of respiratory diseases such as SARS or MERS or influenza,” Hyo-Jick Choi, PhD, Assistant Professor in UAlberta’s Department of Chemical and Materials Engineering, noted in a press release.
So, Choi developed a mask that effectively traps and kills airborne viruses.
Clinical Laboratory Technicians at Risk from Deadly Infectious Diseases
The global outbreak of SARS in 2003 is a jarring reminder of how infectious diseases impact clinical laboratories, healthcare workers, and patients. To prevent spreading the disease, Canadian-based physicians visited with patients in hotel rooms to keep the virus from reaching their medical offices, medical laboratory couriers were turned away from many doctors’ offices, and hospitals in Toronto ceased elective surgery and non-urgent services, reported The Dark Report—Dark Daily’s sister publication. (See The Dark Report, “SARS Challenges Met with New Technology,” April 14, 2003.)
UAlberta materials engineering professor Hyo-Jick Choi, PhD, (right) and graduate student Ilaria Rubino (left) examine filters treated with a salt solution that kills viruses. Choi and his research team have devised a way to improve the filters in surgical masks, so they can trap and kill airborne pathogens. Clinical laboratory workers will especially benefit from this protection. (Photo and caption copyright: University of Alberta.)
How Current Masks Spread Disease
How do current masks spread infectious disease? According to UAlberta researchers:
A cough or a sneeze transmits airborne pathogens such as influenza in aerosolized droplets;
Virus-laden droplets can be trapped by the mask;
The virus remains infectious and trapped in the mask; and,
Risk of spreading the infection persists as the mask is worn and handled.
“Aerosolized pathogens are a leading cause of respiratory infection and transmission. Currently used protective measures pose potential risk of primary and secondary infection and transmission,” the researchers noted in their paper, published in Scientific Reports.
That’s because today’s loose-fitting masks were designed primarily to protect healthcare workers against large respiratory particles and droplets. They were not designed to protect against infectious aerosolized particles, according to the Centers for Disease Control and Prevention (CDC).
In fact, the CDC informed the public that masks they wore during 2009’s H1N1 influenza virus outbreak provided no assurance of infection protection.
“Face masks help stop droplets from being spread by the person wearing them. They also keep splashes or sprays from reaching the mouth and nose of the person wearing the face mask. They are not designed to protect against breathing in very small particle aerosols that may contain viruses,” a CDC statement noted.
Pass the Salt: A New Mask to Kill Viruses
Choi and his team took on the challenge of transforming the filters found on many common protective masks. They applied a coating of salt that, upon exposure to virus aerosols, recrystallizes and destroys pathogens, Engineering360 reported.
“Here we report the development of a universal, reusable virus deactivation system by functionalization of the main fibrous filtration unit of surgical mask with sodium chloride salt,” the researchers penned in Scientific Reports.
The researchers exposed their altered mask to the influenza virus. It proved effective at higher filtration compared to conventional masks, explained Contagion Live. In addition, viruses that came into contact with the salt-coated fibers had more rapid infectivity loss than untreated masks.
How Does it Work?
Here’s how the masks work, according to the researchers:
Aerosol droplets carrying the influenza virus contact the treated filter;
The droplet absorbs salt on the filter;
The virus is exposed to increasing concentration of salt; and,
The virus is damaged when salt crystallizes.
“Salt-coated filters proved highly effective in deactivating influenza viruses regardless of [influenza] subtypes,” the researchers wrote in Scientific Reports. “We believe that [a] salt-recrystallization-based virus deactivation system can contribute to global health by providing a more reliable means of preventing transmission and infection of pandemic or epidemic diseases and bioterrorism.”
Other Reports on Dangerous Exposure for Clinical Laboratory Workers
This is not the first time Dark Daily has reported on dangers to clinical laboratory technicians and ways to keep them safe.
In “Health of Pathology Laboratory Technicians at Risk from Common Solvents like Xylene and Toluene,” we reported on a 2011 study that determined medical laboratory technicians who handle common solvents were at greater risk of developing auto-immune connective tissue diseases.
The UAlberta team may have come up with an inexpensive, simple, and effective way to protect healthcare workers and clinical laboratory technicians. Phlebotomists, laboratory couriers, and medical technologists also could wear the masks as protection from accidental infection and contact with specimens. It will be interesting to follow the progress of this special mask with its salty filter.
University of Turin study in Italy shows under-vacuum sealing systems reduce exposure to formaldehyde by 75% among nurses handling tissue biopsy specimens during surgery
Histology technicians and anatomic pathology (AP) laboratories regularly handle dangerous chemicals such as formaldehyde. They understand the risks exposure brings and take precautions to minimize those risks. However, in operating suites worldwide, nurses assisting surgeons also are being exposed to this nasty chemical.
Nurses must place biopsies and other tissues into buckets of formaldehyde to preserve the tissue between the operating room (OR) and histology laboratory. Formaldehyde, along with toluene, and xylene, is used to process and preserve biopsy tissue, displace water, and to create glass slides. It is an important substance that has long been used to maintain the viability of tissue specimens. Thus, exposure to formaldehyde among nurses is well-documented.
According to a National Academy of Sciences report, formalin, a tissue preservative that is a form of formaldehyde, has been linked to:
Now, motivated by increasing formaldehyde regulations in Europe, as well as the need to increase awareness of exposure risks, the University of Turin (Unito), and other hospitals in Italy’s Piedmont region, conducted a cross-sectional study of 94 female nurses who were being potentially exposed to formaldehyde.
Researchers Aim for “Formalin-Free” Hospitals
The Unito study showed that nurses using an under-vacuum sealing (UVS) system in ORs are exposed to levels of formaldehyde 75% lower than those who did not use the system. This study differs from other similar tests because the level of exposure is not just potential, due to environmental contamination, but confirmed with analytic data from specific urine analyses.
The researchers divided the nurses into two groups:
· One group immersed samples in containers of formaldehyde following standard procedures;
· The other group worked in operating rooms equipped with a UVS system.
The researchers described a UVS system that called for the tissue removed during surgery to be sealed in a medical grade vacuum bag and refrigerated at four degrees centigrade before being transferred to the lab for fixation.
One example of a UVS system is TissueSAFE plus, developed by Milestone Medical, located in Bergamo, Italy, and Kalamazoo, Mich. According to the company’s website, the system, “Eliminates formalin in the operating theatre and allows a controlled formalin-free transfer of biospecimens to the laboratory.”
The image above is from a research paper by Richard J. Zarbo, MD, Pathology and Laboratory Medicine, Henry Ford Health System. It describes “five validation trials of new vacuum sealing technologies that change the approach to the preanalytic ‘front end’ of specimen transport, handling, and processing, and illustrate their adaptation and integration into existing Lean laboratory operations with reduction in formalin use and personnel exposure to this toxic and potentially carcinogenic fixative.” (Image copyright: Henry Ford Health System/Springer International Publishing.)
Increased Scrutiny Leads to New Pathology Guidelines
In a paper published in Toxicology Research, a journal of The Royal Society of Chemistry, the researchers noted a marked difference related to the adoption of the under-vacuum sealing procedure, as an alternative to formaldehyde for preserving tissues. “Nurses, operating in surgical theatres, are traditionally exposed to formaldehyde because of the common and traditional practice of immersing surgical samples, of a size ranging between two and 30 centimeters, in this preservative liquid (three to five liters at a time) to be later transferred to a [histopathology] lab,” the authors wrote. “We evaluated the conditions favoring the risk of exposure to this toxic reagent and the effect of measures to prevent it.”
Throughout Europe, increased scrutiny has forced medical pathology associations to write new guidelines that accept alternative methods to formaldehyde-based tissue preservation methods.
“In Europe, and in Italy in particular, the level of attention to formaldehyde exposure in the public health hospital system has become very high, forcing pathology associations to rewrite guidelines,” Marco Bellini, General Manager of the Medical Division at Milestone Medical, told Dark Daily. “What makes this study unique from many other similar tests is that the level of exposure has been confirmed with data from specific urine analyses,” he added.
The main topic of these guidelines is the preanalytical aspects of specimen collection, transportation, and preservation, where the vacuum method has been indicated as a valid alternative to improve the standardization of these crucial steps in pathology. By moving the starting point for specimen fixation from the OR to the histology labs, parameters can be controlled and documented, with the main advantage of reducing formaldehyde exposure by operators at the collection point.
These guidelines will be presented at the European Society of Pathology (ESP) with the intent to extending them throughout Europe.
Toluene’s and Xylene’s Effects Studied
Formaldehyde is not the only potentially harmful substance in the clinical laboratory. As previously noted, common solvents toluene and xylene also are potentially hazardous.
Medical laboratory leaders are reminded to initiate processes that ensure safe specimen handling, transport, and processing, as well as workflow changes that eliminate chemical odors in the lab. Studies, such as those cited above, may provide information necessary to affect change.
Seeking ways to improve efficiency and cut costs, labs aim to use less formalin
One seldom-reported development in anatomic pathology is the new priority histology laboratories are giving to employee safety. Labs have long recognized that exposure to the dangerous chemicals used in processing tissue creates risk for histotechnologists.
Today, a rising number of medical laboratories in the United States and other countries are seeking to reduce those risks. Routine chemicals still used today in histology include formalin, toluene, and xylene.
National Cancer Institute Report Lists Formaldehyde as a Carcinogen
In August, a scientific body confirmed the risk of using formaldehyde in the workplace. The National Research Council of the National Academy of Sciences issued a report confirming findings in the 2011 National Toxicology Program (NTP) that listed formaldehyde as a carcinogen. (more…)
Study identifies increased incidence of Raynaud’s phenomenon among pathology laboratory staff who work with certain chemicals
Pathologists responsible for health and safety in histology and cytology laboratories will be interested in the results of a newly published study involving staff exposure to certain chemicals. Researchers determined that medical laboratory technicians who handle common solvents develop auto-immune connective tissue diseases in increased numbers.
The new study was published this month in the Journal of Rheumatology. It offers credible evidence that clinical laboratory technicians, pathologists, and scientists who work with toluene and xylene double their chances of developing a vascular condition known as Raynaud’s phenomenon (RP). And for those who work with toluene and xylene combined with acetone or chlorinated solvents, the chance of developing severe RP increases by a factor of nine!
