By Ria Aggarwal
A firefighter's job is one of the most dangerous ones there are. They jump into hazardous areas to protect people and put out the fire, even though there’s a possibility that it could cost them their life. The air they breathe when approaching a fire is toxic, filled with many unfriendly chemicals. One of the deadliest chemicals that firefighters have high exposure to is polycyclic aromatic hydrocarbons.
What are Polycyclic Aromatic Hydrocarbons?
Polycyclic aromatic hydrocarbons also referred to as PAHs, are chemicals that naturally occur in crude, coal, gasoline, and oil. They are formed as a result of burning coal, oil, gasoline, garbage, wood, and tobacco.
There are many different kinds of PAHs. The simplest aromatic hydrocarbon is benzene. The benzene structure has six carbon atoms arranged in the shape of a hexagon, with one hydrogen atom attached to each carbon atom.
The structure of benzene
PAHs contain two or more benzenes connected in different orientations. Therefore, depending upon the number of rings and the orientation, different kinds of PAHs are formed.
This picture shows a few common, simple PAHs
The Effect of PAHs on People’s Health
The full effect PAHs have on people’s health is still unknown. If there are large amounts of Naphthalene in the air, it can cause irritation in the eyes and difficulty breathing. If the skin comes in contact with liquid Naphthalene or its vapors are breathed in, it could be extremely harmful. Blood and liver problems have been seen in workers with large amounts of exposure. Scientists believe that several PAHs in some specific mixture could be carcinogenic.
The Effect of PAHs on Firefighters’ Health
A study was conducted to determine the exposure of firefighters to PAHs. Sixteen Environmental Protection Agency’s (EPA) priority PAHs have been detected on firefighters’ skin, personal protective equipment, working environment, and gas sampling in the fire station and fire engines. They were quantified from wipe samples. The result came back as different PAHs found on the skin (neck and jaw), clothing (zip flap), and fire engines (bodyguard and console). According to the cancer risk factor of 1 in 100,000, up to 350 firefighters may develop cancer from PAHs, up to 230 firefighters could develop cancer from PAHs found on the fire engines bodyguard, and up to 210 firefighters may develop cancer because of PAHs found on the fire engines console.
A Solution for Firefighters’ Protection
Capable of detecting the real-time presence of PAHs in the warm zone during a fire, this sensor was developed by two graduate students from the University of Miami, Chitvan Killawala and Umer Bakali. According to Killawala, “As a consequence, there's very little solid evidence on the levels of PAHs firefighters are exposed to, particularly inside the warm zone of an active fire scene where team staging activities occur and where they aren't suited up in personal protective gear. So, our sensors help fill a void.”
Killawala and Bakali used small commercially available sensors, which were designed to measure vinyl chloride, benzene, as well as other chemicals. "We tweaked their parameters a bit so that we could test for polycyclic aromatic hydrocarbons. The PAHs interact with the sensor and cause a voltage drop, basically a dip in the way that the sensor reads. And that gives us a readout that we can compare to a baseline when there are no PAHs present," Bakali explained.
The two graduate students had to find a way to test the effectiveness of the sensor. They had to position the sensor close enough to the fire. To do so without endangering themselves, they bought a mini remote-controlled monster truck, to which they modified the exterior and placed the sensor on top. They drove the modified rover into controlled fires at multiple fire-training facilities. In a matter of seconds, the sensor provided a readout containing the recorded elevated levels of PAHs. Based on the numbers, it would be wise for firefighters to wear protective gear in the warm zone.
Killawala and Bakali are still modifying their sensor, in hopes to make it much more effective. They plan to do more testing as well. Firefighters that have collaborated with the graduate students are hopeful about the sensor's potential.
The impact the sensor could have may save many firefighters from developing disease. They would know when it’s necessary to wear protective gear, and when it’s okay to go without. Even though the sensor hasn’t been released yet, firefighters must be extremely excited awaiting their new safety feature.