Water – the universal solvent. The all known life on our planet requires it to function, not directly because of water itself, as much as its ability to transport other compounds and ions, and facilitate metabolic reactions. That’s why human civilization itself is based on water, both in determining where people settled, as well as whether they live.
Similarly, many public health studies incorporate water samples into their collection protocols in order to analyze the contents and determine any correlations with various morbidities. Last time in our Amazing Samples blog series, we "cheeked" out some research on buccal cells. This time, let’s wade through some of the research that’s centered on water.
Epidemiology and Water Sanitation
As I already discussed in the Evolution of Public Health Research series, the roots of epidemiology as a stand-alone discipline of medicine started with Jon Snow mapping out the incidence of cholera during the Soho outbreak and finding the correlation to water source. When the people in the area started drinking water from cleaner sources, there was an immediate and substantial decrease in infection rates.
This type of work helped pave the way for Dr. George Kober’s research on water sanitation a few decades later. The Georgetown University professor of hygiene started researching various cities’ incidence of certain diseases, notably typhoid fever, and how said data related to the source of the water. He discussed the decline in associated death rates in English cities after the establishment of sanitary facilities, but more interestingly the strong correlation between various US cities’ water sources and their mean death rates from typhoid fever over a 5-year period.
While the data Dr. Kober analyzed was primarily macroscopic, he presented undeniable proof to the consequences that unclean water has on public health. The roughly concurrent introduction of water chlorination and filtration facilities allowed cities to treat low-quality water and minimize related infections, a cheaper option than changing the actual source of the water. It can be argued, however, that this course of action was not without its consequences, given the increase in synthetic organic chemical manufacturing after World War II – you can read more about that here.
Taking Lead on Drinking Lead
Lead stars in my favorite theory on why the Roman Empire fell: They liked to store and drink their wine from leaden containers because it was sweeter, and consequently lost mental faculty and made all the bad decisions that lead to their own demise. I also find it rather ironic, especially considering that many at the time argued against lead lining water pipes and aqueducts due to the negative health effects.
If you’ve been paying attention to US current events in the past couple of year, or alternatively if you watch John Oliver, then you’re aware that hundreds of different cities have been experiencing dangerously high levels of lead in their drinking water, most infamously Flint, MI. Again, the source of the water is a major factor in these levels, further aggravated by the prevalence of lead-lined pipes in the infrastructure.
Past the obvious discussion of lead’s effect on public health, a relevant lesson came up recently as far as study protocol: the importance of sample collection methodology, and the rationale behind any such planning. Specifically looking at the case of LeeAnne Walters, the city of Flint had tested water samples from her home with already worrisome levels of lead ranging from 104ppb to 397ppb, but researchers from Virginia Tech called the city’s sampling technique into question. These included pre-flushing for a few minutes, which cleared out any lead from the plumbing (leaving only that from the source), and requiring a low flow rate, which reduces collected lead by not agitating as much sediment in the pipes.
The Virginia Tech researchers followed up with their own collection, including samples from multiple different flow rates (low, medium, and high). Their results were shocking, with a few samples qualifying above the US Environmental Protection Agency’s threshold for classifying as “hazardous waste” (The Washington Post has a good collection of images to visualize the range of lead concentrations involved). When the first analytical results came in, the scientists did their due diligence and re-tested the samples with additional checks for quality control, but the original measurements were accurate. These results have helped put further pressure on the city to address the issue, and the ongoing Flint Water Study will be beginning its third round of collections later this month.
Waste Water Not, Want Water Not
Another entire realm of science around water is finding more that can be used. In some cases, it can help support agriculture during a drought, as Chevron is doing in the increasingly arid California. Apparently, for every barrel of oil produced, ten times that volume is brought up in salty wastewater. While not directly a permanent solution, because of the long-term negative effects too much salt could have on crops, some farmers are grateful for any water whatsoever. However, the solution might prove more long-term if they were to use desalination techniques, such as that developed by researchers at MIT two years ago. While scalability is an issue – desalinating drinking water for a small number of villagers is a much easier problem than desalinating the hundreds of gallons of water required for a California farm – the technology’s development gives hope that a viable solution exists, albeit still undiscovered.
In other cases, researchers aren’t just desalinating groundwater or wastewater, but trying to extract fresh water from bodily fluids. While this seems like science fiction (for anyone who’s seen Waterworld), it’s already been used by astronauts due to the difficulty of transporting the heavy liquid into orbit. In fact, the International Space Station is currently looking to replace their current, oversized equipment (up to 150kg) with a far more compact and space-efficient alternative, developed by a Danish company. And you don’t even have to go into space or post-apocalyptic dystopias (arguably) to enjoy some questionably-sourced, but purified and now-technically-potable water – just go to Singapore (or Orange County)! Both trying to shed their reliance on distant sources for their substantial water consumption, the two different water districts have begun recycling household wastewater – predominantly from showers, sinks, and laundry machines. Considering the heavy dependence modern society has on clean water, it’s fortunate that these practices are being pioneered… it almost seems like the hardest part will be changing public opinion.
Do you collect water for your studies? Share your story below! whether you are conducting a phase 3 clinical trial of a new cell therapy or looking for biomarkers, you will need to collect samples, and that leads to a number of questions. Download our eBook below to learn some of the basics to help with planning sample collection and to help make the process as cost-effective as possible.