Water that comes straight from natural sources, dubbed “raw water,” is gaining popularity. Raw water advocates reject public water supplies, including tap water, because they don’t enjoy the taste or believe it’s unsafe and depleted of vital minerals.

On the surface, raw water might seem alluring – the natural surroundings may look beautiful, and the water may look clean and taste refreshing. But unlike tap or commercially bottled water, raw water is not evaluated for safety. This leaves the people who drink it vulnerable to infectious microbes or potentially other toxic contaminants.

I’m a microbiology researcher studying infectious diseases. From a public health perspective, clarifying misconceptions about tap water and the health hazards of raw water can protect consumers and curtail the spread of infectious diseases.

A short history of public drinking water

Archaeological evidence suggests that humans have long associated dirty water with negative health outcomes. As early as 1500 BCE, ancient Egyptians added a binding agent to their water to clump contaminants together for easy removal.

Two major developments in the mid-1800s showed why impure water is dangerous. First, physician John Snow traced a deadly cholera outbreak to contaminated water from London’s Broad Street pump. Second, Louis Pasteur advanced the germ theory of disease, which postulated that microbes can cause illness. Pasteur established that consumable liquids like raw water and milk can harbor disease-causing pathogens.

These discoveries paved the way for large-scale infrastructure projects in the 20th century to ensure the public water supply is safe.

Today, the process of cleaning water begins with the same steps employed by the ancient Egyptians, followed by extensive filtration to get rid of debris as well as most germs and chemicals. Chlorine is added to kill lingering pathogens, including those that may reside in the service pipes carrying the water to the faucet. Beginning in the 1940s, a small amount of fluoride was added as an inexpensive, safe and effective means to improve dental health.

The cleanliness and fluoridation of the water supply has dramatically reduced infectious disease and cavities, and has been heralded as one of the 20th century’s greatest public health achievements.

Is raw water healthier than tap water?

People who champion raw water claim it has health benefits, such as essential minerals and beneficial bacteria called probiotics, that are stripped from tap water. Let’s unpack each of these claims.

Water dissolves bits of soil and rock at its source; therefore, its mineral content depends on the local geology. Areas with a lot of limestone, like the Midwest, have water that is higher in calcium. Water from deeper in the ground may have higher mineral content since it passes through more rock on its way to the surface.

The idea that tap water is depleted of essential minerals is not true, as these nutrients are too small to be excluded by the filtration process. Test kits can determine the mineral content of your water, and if you find it lacking, mineral supplements can be added. Experts suggest, however, that most minerals you need come from your diet, not water.

Some also claim that raw water contains probiotics that are removed from tap water. The amount of probiotics in water would also vary by location, and the notion that health-promoting bacteria reside in raw water has not been proved.

There are no studies associating raw water with any health benefit. Anecdotal claims about smoother skin or increased energy are likely to be placebo effects. Even the idea that raw water tastes better might be more psychological than physiological – a 2018 study showed that most people preferred tap water over bottled water in a blind taste test.

Risks of drinking raw water

Raw water carries the risk of serious gastrointestinal infection from a wide variety of pathogens.

Water-borne viruses include rotavirus and norovirus, which cause rapid-onset diarrhea and vomiting, and hepatitis A, which infects the liver. Bacteria such as E. coli and Salmonella, or parasites like Cryptosporidium and Giardia, also cause severe diarrhea that can lead to dangerous levels of dehydration. Toxoplasma gondii can also lurk in raw water and can cause miscarriage or birth defects if consumed during pregnancy.

Carriers of diarrheal infections can transmit them to others if they swim in public pools or fail to properly wash their hands before touching others or preparing food. Norovirus is particularly durable and can survive on surfaces for days, increasing chances of it infecting someone else.

Raw water can also contain algae that release toxins causing abdominal issues and damage to the brain and nervous system.

Cholera, dysentery and typhoid fever are no longer health burdens in the U.S. thanks to a robust water treatment system. But areas of the world lacking this privilege suffer high child mortality and widespread diarrheal diseases.

How safe is tap water in the US?

Tap water in the U.S. is among the safest to drink in the world. The Biden administration took steps to further improve it, including funding to replace lead pipes and new rules to monitor forever chemicals like perfluoroalkyl and polyfluoroalkyl substances, or PFAS, which have been linked to cancer and developmental disorders.

Importantly, raw water is not necessarily free from lead, arsenic, pesticides or industrial contaminants. Raw water sources are not reliably monitored by experts, so it is difficult to say which ones pose less risk. In addition, the water may be acceptably safe one day, but not on another. For example, soil runoff from a storm could introduce new germs or pollutants into the area.

The Environmental Protection Agency routinely screens for nearly 100 contaminants to ensure tap water is safe. In contrast, raw water remains untested, unregulated and untreated, leaving its safety to drink in question. In terms of risks and benefits, there are no demonstrated health benefits from drinking raw water, but clear evidence that you may be exposing yourself to harmful infectious and toxic contaminants.

Bill Sullivan, Professor of Microbiology and Immunology, Indiana University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

In the early days of the second Trump administration, a directive to pause all public communication from the Department of Health and Human Services created uncertainty and anxiety among biomedical researchers in the U.S. This directive halted key operations of numerous federal agencies like the National Institutes of Health, including those critical to advancing science and medicine.

These operations included a hiring freeze, travel bans and a pause on publishing regulations, guidance documents and other communications. The directive also suspended the grant review panels that determine which research projects receive funding.

As a result of these disruptions, NIH staff has reported being unable to meet with study participants or recruit patients into clinical trials, delays submitting research findings to science journals, and rescinded job offers.

Shorter communication freezes in the first few days of a new administration aren’t uncommon. But the consequences of a freeze lasting weeks or potentially longer underscore the critical role the federal government plays in supporting biomedical research. It also brings the intricate processes through which federal research grants are evaluated and awarded into the spotlight.

I am a member of a federal research grant review panel, as well as a scientist whose own projects have undergone this review process. My experience with the NIH has shown me that these panels come to a decision on the best science to fund through rigorous review and careful vetting.

How NIH study sections work

At the heart of the NIH’s mission to advance biomedical research is a careful and transparent peer review process. Key to this process are study sections – panels of scientists and subject matter experts tasked with evaluating grant applications for scientific and technical merit. Study sections are overseen by the Center for Scientific Review, the NIH’s portal for all incoming grant proposals.

A typical study section consists of dozens of reviewers selected based on their expertise in relevant fields and with careful screening for any conflicts of interest. These scientists are a mix of permanent members and temporary participants.

I have had the privilege of serving as a permanent chartered member of an NIH study section for several years. This role requires a commitment of four to six years and provides an in-depth understanding of the peer review process. Despite media reports and social media posts indicating that many other panels have been canceled, a section meeting I have scheduled in February 2025 is currently proceeding as planned.

Reviewers analyze applications using key criteria, including the significance and innovation of the research, the qualifications and training of the investigators, the feasibility and rigor of the study design, and the environment the work will be conducted in. Each criterion is scored and combined into an overall impact score. Applications with the highest scores are sent to the next stage, where reviewers meet to discuss and assign final rankings.

Because no system is perfect, the NIH is constantly reevaluating its review process for potential improvements. For example, in a change that was proposed in 2024, new submissions from Jan. 25, 2025, onward will be reviewed using an updated scoring system that does not rate the investigator and environment but takes these criteria into account in the overall impact score. This change improves the process by increasing the focus of the review on the quality and impact of the science.

From review to award

Following peer review, applications are passed to the NIH’s funding institutes and centers, such as the National Institute of Allergy and Infectious Diseases or the National Cancer Institute, where program officials assess the applications’ alignment with the priorities and budgets of institutes’ relevant research programs.

A second tier of review is conducted by advisory councils composed of scientists, clinicians and public representatives. In my experience, study section scores and comments typically carry the greatest weight. Public health needs, policy directives and ensuring that one type of research is not overrepresented relative to other areas are also considered in funding decisions. These factors can change with shifts in administrative priorities.

Grant awards are typically announced several months after the review process, although administrative freezes or budgetary uncertainties can extend this timeline. Last year, approximately US$40 billion was awarded for biomedical research, largely through almost 50,000 competitive grants to more than 300,000 researchers at over 2,500 universities, medical schools and other research institutions across the U.S.

Getting federal funding for research is a highly competitive process. On average, only 1 in 5 grant applications is funded.

Consequences of an administrative freeze

The Trump administration’s initial freeze paused some of the steps in the federal research grant review process. Some study section meetings have been postponed indefinitely, and program officials faced delays in processing applications. Some research groups relying on NIH funding for ongoing projects can face cash flow challenges, potentially resulting in a need to scale back research activities or temporarily reassign staff.

Because my own study section meeting is still scheduled to take place in February, I believe these pauses are temporary. This is consistent with a recent follow-up memo from acting HHS Secretary Dorothy Fink, stating that the directive would be in effect through Feb. 1.

Importantly, the pause underscores the fragility of the research funding pipeline and the cascading effects of administrative uncertainty. Early-career scientists who often rely on timely grant awards to establish their labs are particularly vulnerable, heightening concerns about workforce sustainability in biomedical research.

As the NIH and research community navigate these pauses, this chapter serves as a reminder of the critical importance of stable and predictable funding systems. Biomedical research in the U.S. has historically maintained bipartisan support. Protecting the NIH’s mission of advancing human health from political or administrative turbulence is critical to ensure that the pursuit of scientific innovation and public health remains uncompromised.

Aliasger K. Salem, Associate Vice President for Research and Professor of Pharmaceutical Sciences, University of Iowa

This article is republished from The Conversation under a Creative Commons license. Read the original article.