Is there plastic in your drinking water?

I first came across this question through a link on Intrigued and somewhat terrified, I followed the link to a webpage by Orb Media titled Invisibles: The plastic inside us. After reading the webpage I was awe-stricken yet curious for some clarification.

Firs off allow me to quickly sum up the report and, maybe, completely scare the s*#$ out of you.

OrbMedia and a few of its institutional partners collected 159 tap water samples from seven different regions: the United States, Beirut, Europe, Jakarta, Kampala, New Delhi, and Quito. These samples were sent to a lab at the University of Minnesota School of Public Health where they were tested by researcher Mary Kosuth. Each sample underwent vacuum filtration after which the filtrate was treated with Rose Bengal, a stain that binds to organic material. The researcher then used a microscope to examine the filtrate, and any unstained particles were agitated with a micro spatula. Particles that endured this test without breaking were deemed inorganic and plastic. Of the 159 samples, 83% were found to contain at least one micro plastic fiber. After adjusting for sample size, the data summary of the report concluded that this value was somewhere between 69% and 92%. According to the average contents, if you drink 3 liters of water a day that adds up to 14 plastic particles and 4,000 annually! Gross!

Final Report Figure 2

Furthermore, OrbMedia’s webpage suggests that plastics absorb toxins more readily than most other environments. When fish are exposed to plastics, digestive enzymes can release the absorbed toxins into the body. OrbMedia proposes that humans should be quite concerned about this phenomenon taking place in our own bodies.

… Does anyone else feel the desperation of a child who thinks an apple seed might sprout into a tree inside his stomach?

Final Report Picture 1

Before diving into too much of a tailspin, let us take a look at the fine print and the in-between the lines. Despite what the title of the report suggests (Synthetic Polymer Contamination in Global Drinking Water) not all of the samples were actual drinking water. All samples came from the tap, but only half came from taps that residents would drink from. This accounts for a significant number of the 159 samples. If all of these samples contained plastic and the true worldwide average for plastic particles is 69%, then the remaining 19% of contaminated samples came from actual drinking water. Though still unsettling, this figure is markedly  better than the aforementioned 83% or 92%.

I also found issue with the methods of the experiment. Inorganic particles (particles that were not stained by Rose Bengal) were subject to mechanical stress by a micro spatula. If the particle did not break under stress it was categorized as plastic. What about non-plastic particles that are insoluble in water? Examples include metals like iron or salts like magnesium hydroxide. These elements and compounds do not contain carbon (therefore they are not organic) and could be relatively challenging to break with a spatula. Imagine the difficulty of breaking a single grain of salt with a knife. I’m not sure that inorganic particles were incorrectly identified as plastics, but I believe the possibility exists.

Finally many of the fear-inducing statements included in the main webpage are not followed by data or sources. In my opinion this is perhaps even more concerning than citing a flawed study. The audience is simply left to accept the statements as truth.

There is no question that the topic of this blog post and corresponding article poses a great threat to the environment and public health. I would prefer not to have any micro plastic fibers in my water, let alone my body. However more research should be conducted before conclusions are made, and the claims in these documents should be taken with a grain of salt.


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