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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!

Majority of Cases Involve Women Who Work in Pathology Laboratories

The study was conducted at the University of Otago, in Wellington, New Zealand. Researchers asked all the histology laboratories and cytology laboratories in New Zealand to participate in the study. Every laboratory department in the nation agreed and provided data and access to laboratory workers.

A total of 341 medical laboratory technicians participated in the study, most of whom were women (79%). Those who came into contact with toluene and xylene on a regular basis were twice as likely to develop Raynaud’s phenomenon. However, those who worked with acetone or chlorinated solvents combined with toluene and xylene were nine times more likely to develop severe Raynaud’s phenomenon.

Skin discoloration caused by Raynaud’s phenomenon, which can also lead to necrosis and gangrene. (Image sourced from

“I am concerned that 75% of those who worked with xylene or toluene handled wet sample slides without gloves. The majority had done so daily for over a decade,” said lead researcher Gordon Purdie, BSc, who is a biostatistician. “Absorption through the skin is a classic way for solvents to have a negative impact on health.”

As those working in histology or cytology labs know, these solvents are used during tissue processing to produce microscopic slides for viewing by pathologists. Researchers concluded that constant exposure to solvents is a contributing fact in the increased cases of Reynaud’s phenomenon among the study’s participants.

According to the study, medical laboratory workers who did not handle solvents developed severe Reynaud’s phenomenon at the same rate as people who did not work in medical laboratories at all. The researchers could therefore conclude that the increased incidence of Reynaud’s phenomenon cases among histology and cytology laboratory workers was the direct result of exposure to solvents.

Symptoms of Raynaud’s Phenomenon

Traditionally, Raynaud’s phenomenon results from exposure to cold or emotional stress that causes blood vessels in the hands, feet or other extremities to spasm. The alternating constricting and dilating of the vessels are called vasospastic attacks. They decrease the blood flow to those areas resulting in discoloration, and in extreme forms, can cause the skin to atrophy and lead to gangrene and necrosis.

This is the first study to demonstrate a link between medical laboratory worker solvent exposure and symptoms of auto-immune connective tissue disease, and has important implications for workplace health and safety,” said Andrew Harrison, Ph.D., a Senior Lecturer in Rheumatology at the University of Otago, and co-author of the study.

Study May Encourage Pathologists to Adopt Alternative Processing Methods

It is likely that this new study by the researchers at the University of Otago will motivate other researchers to also study the health impact of working with the solvents and chemicals commonly found in histology and cytology laboratories. The use of these chemicals for purposes of tissue processing and fixation is widespread. Thus, the findings of this study, if confirmed by future studies, will likely spur pathologists and histology laboratory managers to take steps to reduce staff exposure to these chemicals.

There are alternative methods for processing and fixing tissue that do not involve the chemicals that were the subject of the University of Otago study. One company that is a pioneer in developing automated tissue processing systems that don’t require formalin and similar chemicals is Milestone Medical. It offers an automated tissue processing system that allows the operator to choose “formalin or formalin-free fixation” and “xylene or xylene-free clearing.”

Milestone Medical may be among the first of the histopathology companies to recognize the demand by some histology laboratories for automated processing solutions that reduce the staff’s direct exposure to chemicals. But with this study, which links exposure to xylene and toluene to a higher incidence of Raynaud’s phenomenon, it is likely that more pathology laboratories will now want to look at how to reduce staff exposure to these chemicals—and possibly even eliminate their use.

Pathology groups and histology laboratories will probably also want to assess how this new research study might change the legal liability that the laboratory has, as it pertains to employees who have decades of exposure to xylene, toluene, and similar chemicals, and who may also show the symptoms of Raynaud’s phenomenon. In the United States, it doesn’t take long for attorneys to recognize a new legal cause of action and begin advertising to find individuals willing to be the plaintiff in a lawsuit.

Finally, it must be acknowledged that there is already a growing trend to re-design histology and cytology laboratories so that the odor from these chemicals is eliminated. In addition, enhanced use of automation and workflow redesign techniques reduces the direct exposure lab staff has to such chemicals. The findings from this new study linking use of xylene and toluene to Raynaud’s phenomenon may serve to accelerate this trend, for all the right reasons pertaining to staff safety.

Related Information:

Health Risk from Solvent Use by Lab Technicians (Press Release)


Questions and Answers about Raynaud’s Phenomenon

Comparison of Formalin-Free Tissue Fixatives: A Proteomic Study Testing Their Application for Routine Pathology and Research

Comparison of Formalin-Free Tissue Fixatives: A Proteomic Study Testing Their Application for Routine Pathology and Research (Archives of Pathology & Laboratory Medicine)