From pink eye to MRSA, septic service technicians are at great risk for pathogen exposure, according to a Washington state study.
Hundreds of infectious agents live in human waste. The bad news is that many workers in the industry are not properly protecting themselves. The good news is that it’s relatively easy to upgrade personal protective equipment (PPE) to shield field technicians from the bacteria, viruses, protozoa and parasites found on the job.
The risk is made clearer by a 2013 study of pathogen exposure by the Washington On-Site Sewage Association, according to Executive Director John Thomas. A $138,005 Safety and Health Investment Project (SHIP) Grant from the Washington State Department of Labor & Industries funded the WOSSA field and laboratory study.
The funding support of the LNI SHIP Grant provided WOSSA a way to bring this information to the industry.
As part of the grant, WOSSA developed classroom-training materials that will be used in Washington to raise awareness of the issue and the exposures. WOSSA is making the training materials available to other states. Thomas began presenting the information in training sessions in 2014.
Pumper: What did you learn from the study?
Thomas: There are pathogens in wastewater that are commonly known and we understood the frequency of exposure for some service providers is extremely high, but the study identified some new pathogens. In addition, we observed that the current selection and use of personal protective equipment is inadequate or not used at all. There are more than 100 known viruses and more than 100 known bacteria in wastewater that can make you sick. We found viable MRSA bacteria, a staph infection resistant to antibiotics, in liquid sampling. Once you get it, it is very hard to get rid of. We also had positive tests for a family of bacteria that includes chlamydia, a sexually transmitted disease, from aerosolized wastewater being dumped at a septage handling facility.
The most common exposures came from direct contact with wastewater through immersion, splash back and exposure to aerosols created by work activities. We found exposures as far as 90 feet from the equipment. But we also looked at how workers were exposing themselves to contamination. We observed pumpers who on a typical 45-minute job touched their face 18 times, putting themselves at risk of direct exposure to pathogens. On hot days, sweat dripping into their eyes contributes to things like pink eye. When we tested electronics worn on the job site, we found cellphones contaminated with E. coli.
Pumper: Was there anything that surprised you?
Thomas: Exposure to pathogens by splash back or immersion is obvious, but probably the most surprising thing we observed was the scope of the inhalation exposure to airborne pathogens. This was caused by the creation of aerosols with different work activities like jetting or back flushing into the tank. Another common practice seen was a pumper washing down the sides of the septic or pump tank and then pumping out the residual water. Our testing showed the aerosol cloud was much bigger than we thought. We also found that the air venting out of the bottom of the pump truck during pumping also gave positive hits for pathogens as far as 60 feet away.
Pumper: What are you hearing in the classes where you are presenting this information?
Thomas: The feedback has been very positive and comments written are things like, “Everyone in our industry should have to take this course; it should be mandatory.” It was surprising that in nearly every class we’ve done someone has come up afterward with their story about getting sick, from pink eye to infections and the “poop flu.” We heard from one individual who was hospitalized for a week with an extensive MRSA infection on his face and in his sinuses. He was able to directly relate it to a job he was working on where he thinks he was exposed. The infection was on his face and sinuses because he breathed it in when the tank vented. He opened it without wearing any kind of a respiratory mask and he and his co-worker were both exposed.
The study identified two cases of pink eye from getting sewage in the eyes that required emergency room treatment, a case of Giardia [caused by a parasite] from an open wound exposed to sewage, and cases of hepatitis and E. coli from companies participating in the training. Public beaches are closed in Washington when E. coli reaches 126 colony forming units per 100 mL. In our field samples, raw sewage commonly contained 160,000/100 mL. It really helps to put the issue into perspective for workers to consider the concentration and frequency of exposure they have on a daily basis.
We see a dichotomy of opinions on the issue. Many older workers say they’ve been pumping out septic tanks for years without getting sick. Nearly 100 percent of the younger workers interviewed are telling us they’ve gotten sick with flu-like symptoms in the first six months and think it was from the job. Because the flu-like symptoms often resolve after a week or so, it is often blamed on something else.
Some good news is the positive impact of the training that we’ve presented results in people making some changes after they’ve had some time to think about what we presented. In addition, some employers are changing out the PPE to make sure they are fit for use and are designed to give workers the proper protection from pathogens.
Pumper: What is the right PPE?
Thomas: Depending on the task, there are different levels of PPE you should be using. A few simple things can really improve the level of protection. We often see guys using basic work gloves or nitrile gloves for a large number of tasks. As we evaluated these we found two things. First, the nitrile gloves, rated for “industrial use,” didn’t have the durability for the work and would come apart. They were the wrong kind of nitrile gloves to begin with. There’s a difference between gloves rated for industrial or “food handling” and those rated “exam” quality, often referred to as medical gloves. Our industry should be using exam-grade gloves with a minimum thickness of 4 to 6 mil for durability. The industrial grade or “mechanic’s gloves” may keep your hands cleaner, but they don’t protect you from the pathogens.
Other exposures can be effectively managed with a couple of simple changes. When aerosols are being created by jetting, back flushing or during the operation of the pump truck, make sure employees are using the appropriate kind of face protection to prevent inhalation. A lot of employers provide dust masks or other kinds of facemasks. Upgrade them to an N95 surgical mask, sometimes called a procedure mask, and that will give them appropriate protection for airborne pathogens. One field test of an N95 mask showed it had more than 10,000 colonies of bacteria on it. A simple dust mask is not designed to protect a worker from that kind of exposure.
Eye protection should protect from splashes, sprays and airborne aerosols from multiple angles, so goggles are sometimes needed rather than just a pair of safety glasses.
Pumper: What else does this information tell the industry about safety?
Thomas: Reducing exposure to pathogens is a responsibility under OSHA’s [U.S. Occupational Safety and Health Administration] General Duty Clause and state labor and industry requirements to provide a safe workplace. There are simple steps to do that without costing a lot more money than they’re spending now to make sure their employees are adequately protected.
In our literature review at the beginning of this study, the information about pathogens and PPE was principally around wastewater treatment plants. Those are closed systems; the exposure we have is different. When someone pulls up to a house to pump out a septic tank, he has no idea of the health of the occupants of the house. Whatever illnesses or infections they have are in the sewage and the infective dose threshold for many pathogens is quite low. For worms and viruses in sewage, it just takes one to make you sick. That’s the challenge for employers under the General Duty Clause, to understand what the exposures are so they can take the proper steps to mitigate them.
Folks in the industry will build up immunities over time, but having found something on the high end of the spectrum like MRSA – that public health departments have found widespread in communities in just one septic tank – means there is potential for it in any septic tank, so that’s the exposure level they have to protect their employees against.
Pumper: Do you think more regulation is needed in this area?
Thomas: Good question, but the answer is not easy since sewage is generally not a regulated waste like bloodborne pathogens and you don’t need placarding to transport it. As we’ve worked with the Washington State Department of Labor & Industries, we’ve found there really isn’t a designated category for us as an industry classification. The closest we get to it is the bloodborne pathogen rules that seem to be affiliated with biological exposures more than any other rule. It describes employer responsibility for exposures of workers in direct contact with blood and body fluids like you’d expect in a health care setting, but throughout the language it talks about employer responsibility for employee exposure to something called OPIM or “other potentially infectious material,” which seems to include any other pathogen exposures that can make you sick. It is something that people should review and consider.
As we reviewed it with the technical support staff from the Department of Labor & Industries, they suggested that we may have to get involved in some rule-making to get some clarity on how these safety practices apply to our industry in Washington.
Pumper: What is this knowledge going to do for the industry?
Thomas: We hope education and awareness will effect real change for how safety happens in our industry. It is important information that will have a positive impact and, with a few simple steps, reduce both the exposures and the number of work days lost to illness.