What can your jewelry tell you about your carcinogen exposure? Not much in most cases – unless you are wearing a bracelet or dog tag dosimeter designed to measure and monitor chemical exposure.
The trackers: Wristbands and dog tags
The technology was initially developed by Dr. Kim Anderson at Oregon State University over the course of four years. She and her team developed a wristband that is “clean” – clear of chemical contamination – that firefighters can wear to track exposure to toxins. With feedback from focus groups of firefighters, they also developed a dog tag dosimeter for firefighters to wear both on and off duty. Firefighters felt the dog tags would be an easier way to collect carcinogens, particularly given that they hang closer to the neck area, which often sees more exposure and is particularly vulnerable to dermal absorption.
The tags and wristbands are engineered to mimic the uptake of skin and lung cells when exposed to chemicals. Currently, the silicone can absorb and detect the presence of 1,530 different semi-volatile and volatile organic compounds (SVOCs and VOCs). These are classes of organic chemicals that are released into the air from products or processes such as paint, adhesives, furniture, pesticides, diesel emissions, and wood-burning stoves. Many of the chemicals are considered known or suspected carcinogens.
Dr. Anderson and her team have previously studied chemical exposures among pregnant women and roofers as well as flame retardant exposure in preschool children and pesticide exposure among farm workers. She has recently turned her efforts to understanding the exposures of firefighters.
The results: On-duty vs. off-duty exposure
At the conference of the Society of Environmental Toxicology and Chemistry in Toronto, Dr. Anderson’s doctoral student Carolyn Poutasse presented preliminary findings from their FEMA-funded study looking at firefighters’ exposures both on and off duty.
They collected exposures over the course of 30 on-duty shifts and 30 off-duty days at one high and one low call volume department. A total of 110 dog tag samplers were screened for 1,530 target analytes using a gas chromatography mass spectrometry analysis refined by the Oregon State research team. Of the dog tags analyzed, 101 target analytes were detected.
Not surprisingly, on-duty exposures to phthalates and industrial chemicals were significantly higher on duty than off. Analytes detected included di-n-butyl phthalate (a manufactured chemical commonly added to paint, glue, plastics and other household products), di(2-ethylhexyl) phthalate (commonly added to plastic to make it flexible) and benzothiazole chemicals (from rubber) that have been found to be possibly or probably carcinogenic or have reproductive effects.
Importantly, no two chemical exposure profiles from the dog tags were the same despite firefighters being on the same crew and in the same environment. This finding suggests that there is a significant amount of variability in individual exposures depending on task and mitigation strategies. Further, the finding is important because many assessments of exposure are measures of what is present on the fireground but less focused on what individual firefighters are exposed to in that setting.
Given the success and sensitivity of the dosimeter, future research can focus on different exposures specific to the fireground (e.g., interior firefighting vs. search and rescue) as well as exposures at different types of fires (e.g., room and contents vs. car).
Another study: Silicone dosimeters deployed in Florida
Dr. Alberto Caban-Martinez, deputy director of the Firefighter Cancer Initiative at the Sylvester Comprehensive Cancer Center at the University of Miami, recently presented the results of his work with silicone dosimeters at the American Association for Cancer Research annual conference in Atlanta.
In Dr. Caban-Martinez’s study, the team deployed 24 wristbands across fire departments in south Florida for 24 hours. They analyzed their silicone wristbands for polycyclic aromatic hydrocarbons (PAHs) using gas chromatography mass spectrometry. They found an average of 23 chemicals classified as carcinogenic, including benzo[b]fluoranthene, benzo[j]fluoranthene, chrysene and naphthalene.
All bands collected had at least one PAH present with most containing benzo[b]fluoranthene (present in coal and petroleum products) and chrysene (found in coal tar), half containing benzo[j]fluoranthene (present in gas and coal emissions), and all containing naphthalene (present in car exhaust and pesticides) – all of which have been classified as probably or possibly carcinogenic.
Personal exposure tracking
The future of these types of passive samplers will likely extend beyond the research realm. In the future, the dosimeters may be useful to firefighters who want to document their own exposure levels.
A challenge to current workers’ compensation coverage is often proving exposure. While many cases hinge on documenting exposures by logging calls with an assumption that the firefighter was exposed to carcinogens, this technology can provide personalized exposures documentation.
Until the technology is widely available, it is important for firefighters to continue tracking their call responses either through paper/pencil measures or through electronic apps, such as the National Fire Operations Reporting System (NFORS).
