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Toilet Thoughts: What about Chemo?

Updated: Jun 11, 2023

With continued conversations on the reuse of fecal waste for agricultural products, there has been growing concern and questions about ensuring our sanitation systems don’t contaminate our environment with things like PFAS, microplastics, and pharmaceutical drugs. We at FLUSH wanted to explore an unknown and rarely researched topic – chemotherapy (“chemo”) and its effects on toilets, waste, and the environment. We looked into how chemo changes how people use toilets and its overall effects on our sanitation systems and environment.

Background on Cancer and Chemotherapy

The World Health Organization defines cancer as a large group of diseases that can start in almost any organ or tissue when abnormal cells grow uncontrollably and invade other body parts. Cancer is considered the second leading cause of death globally, accounting for nearly 10 million deaths in 2020, or nearly one in six deaths. It is also estimated to grow to more than 17 million new cases by 2040; with about 50% of cases needing chemotherapy treatment.

Chemotherapy is a treatment option used to kill fast-growing cells in your body; for most, it is most commonly associated with cancer treatment. When a patient receives chemotherapy, the goals are to cure, control, and palliate. A cure is when treatment can destroy cancer - without returning. Controlling and managing cancer is when a cure is impossible but can be treated as a chronic disease, like diabetes. Lastly, palliative care is when chemo can ease symptoms and reduce pain for those with more advanced cancer who may be towards the end of life.

Cancer is a disease that wreaks havoc on people and their loved ones’ lives; chemotherapy has completely altered their everyday routines - even how to use the bathroom. In the next section, we’ll look to see what toilet habits change when someone is undergoing chemo.

Chemo and Toilet Use

Chemotherapy drugs are considered hazardous to all who come into contact with them. This is due to the powerful chemicals within each dose that can be harmful to cell growth for those who do not have cancer. As a result, there are specific, strict procedures for handling these drugs, even down to what leaves your body!

A hospital bathroom sign (Credit: FLUSH/K Worsham)

When chemo drugs exit the body, fecal waste is considered hazardous. For 48 to 72 hours after undergoing a chemo session, patients are supposed to follow specific procedures on waste management. Because of the harm that chemo excretion and contamination can do to those not taking chemo, experts recommend using a different bathroom than loved ones who are (especially children and pregnant women). We recently spoke with our friend Dr. Andrew Yang, an oncologist at The Everett Clinic. According to Dr. Yang, not all chemo drugs will be excreted as active agents. For example, specific ingredients in chemo drugs like cyclophosphamide are excreted out of urine at about 10-20% active. On the other hand, another ingredient like doxorubicin is excreted as an active drug from poo at 40%, which is pretty high! With any unprotected contact with the skin, it can cause negative effects. Additionally, the patient must flush the toilet twice after each use and the bathroom to help dilute the chemo in the wastewater system.

But little to no information is known on how chemo patients should be handling their waste when using waterless toilets or in areas where sanitation systems are underdeveloped. For example, what if someone receives chemo treatment while using pit latrines with squat toilets?

Chemo and Bathroom Cleanup

With our limited understanding of how chemo waste is handled, most professionals also consider that chemo patients should treat their waste like biomedical waste. That means that bathrooms used when someone has chemo should also be cleaned with proper personal protective equipment (PPE) on at all times because of the treatment’s hazardousness. For chemo, proper PPE includes face masks, gloves, and goggles that can protect you from contact with anything that has active chemo chemicals, including urine, stool, and sweat. The same PPE requirements go for those wearing disposable adult diapers. Again, experts recommend that those using disposable adult diapers, underwear, or sanitary pads discard them by sealing them in TWO plastic bags (as in, one plastic bag in another) before throwing them away with the regular trash.

These practices bring questions if this should be the proper disposal method of materials in contact with chemo residues. For example, could chemo be affecting our environment or sanitation workers who may come into contact with waste soiled with chemo-infected feces? A good step would be for hazardous material bins to be provided for those using this option to prevent improper disposal within our environment. These bins would then be handed over to local hazardous waste management authorities, who hopefully have protocols for this waste. But that conversation is still ongoing.

If we were to consider this biomedical waste, should there be an alternative method to handling this waste? What could it be doing to the patients’ sanitation systems? With chemotherapy treatment expected to increase, what is the impact of this waste on our environment?

Chemo and Waste Treatment

We know there are strict procedures in handling chemo-dosed waste; because of that, waste that has chemo in it should not be reused for any reason. With that being understood, what could it be doing to our septic tanks and sewer systems?

Generally, sanitation systems take in organic matter, floatable matter (like grease), and solids from wastewater. Septic tanks discharge the liquid part of wastewater into perforated pipes within leach fields, or specialized units designed to slowly release this liquid into the soil, eventually getting into groundwater. That means that chemo residues could leach into our soils and groundwater, but it’s hard to calculate how it could impact our environment; we haven’t found any information about that, at least.

Sewer systems move the wastewater from home to the wastewater treatment plant. That means that chemo residues are flushed to wastewater treatment plants. It is concerning that wastewater treatment plants can only remove 2% of these active chemicals. The other 98% of active chemicals may get discharged into lakes, rivers, and ponds. Still, we’re not sure how this changes or hurts our waterways and ecosystems.

Circling back to our conversation with Dr. Yang, he mentioned that little to no information is known on the effects of these micro toxins in drinking water or the environment. Additionally, medical professionals believe that we have constant exposure to various microtoxities. These microtoxicities end up accumulating and causing health and environmental damages; we cannot simply narrow down chemo drugs as the culprit! This makes understanding the direct impacts really tough.

It's Worth Considering

When considering all this uncertainty about the impacts of chemo waste, a thought worth considering more research and understanding by healthcare and sanitation professionals: is there another way?

We understand that reusing waste laced with chemo residues in the environment is not recommended. Therefore, what are the effects of it leaching into groundwater? How can we ensure that chemo drugs don’t contaminate our water systems? What would happen to our agriculture if our composted fertilizer included active chemo residues?

We also need to consider what about those who live in environmentally hazardous regions that lack good access to sanitation systems - what are the effects on their communities? We should look at the disproportionate lack of reform for vulnerable communities – such as black communities in the south - that suffer from poor sanitation and environmentally-damaged ecosystems. What are their cancer rates, and is it exacerbated by sanitation that is not safely managed and pollutes their land and water?

We do not want to exaggerate the challenges that chemotherapy drugs bring to our environment. Instead, we want to highlight a gap in our evidence base about how it works out. Our call to action is to continue researching how chemo - and other hazardous materials (including medical residuals) - impact our sanitation systems and what to do about it. For example, we can test chemo patients’ septic systems, their family’s health, and whether active chemo chemicals are in their local drinking water sources.

Whatever steps are taken can potentially open up an entirely new discussion on how to keep our cancer patients safe; down to their poop!

Updated June 2023 to include a new image from a hospital in the US.

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