Pesticides and Water Quality


In modern agriculture, almost everything is grown with the help of pesticides. When these chemicals are sprayed on nearly everything we eat, we must ask: can they harm us?

Rachel Carson's book Silent Spring put the toxic and damaging effects of Dichloro-diphenyltrichloroethane (DDT) on the map in 1962, inciting a global conversation about the environmental and public health dangers of widespread pesticide use. 

The word “pesticides” refers to chemicals used to kill or deter pests. Different pesticides are used on different pests: herbicides for weeds and insecticides for insects, for example. Though some older, harmful pesticides (like DDT) are now banned, over 1,000 pesticides are still used globally, each with its own properties and human health effects.

So they kill weeds and pests, but what about humans? We help break down how pesticides can get in water and what their impacts could be on your health.

How Do Pesticides Get Into the Water Supply?

One of the primary ways that pesticides work their way into the water supply is by seeping through the soil to the groundwater. Around 50 percent of people in the US — and about 95 percent of those living in agricultural areas — rely on groundwater for drinking water.

Pesticides are most widely used in agricultural areas, so concentrations of pesticides are usually higher in those regions. Once in the environment, however, pesticides can easily spread, ending up in water through many paths: precipitation, leaching, runoff, and wind, for example.

This process can take years for chemicals to work their way through soil to the groundwater, creating a time lag between pesticide use and appearance in deeper water reserves. Once there, chemicals can stay in groundwater for decades, even if efforts are made to reduce pesticide use above ground.

Changing Pesticides, Changing Risk

Protecting crops and increasing yields has been a goal for decades now. Chemicals have been used to achieve that goal for as long, but the kinds of chemical used have changed.

Before the 1940s, compounds that included arsenic, mercury, or lead were common. Though these chemicals pose serious threats to human health, they are not very soluble, so they turned up in food more often than in water.

After World War II, pesticides shifted towards synthetic organic compounds, which were thought to be safer. These compounds, including chlorinated hydrocarbons such as DDT, are more attractedto soil than water, and so they tend to accumulate in soil and food chains as opposed to water.

When the toxic health effects of these chlorinated hydrocarbons were discovered, an effort began to replace them with safer, less toxic chemicals. One group of these new pesticides are called carbamates, and they are highly soluble in water.

Thus, while pesticides may be trending safer, they may also appear more frequently in our water sources. Long-term studies are still underway to figure out what the health effects are, but in the meantime, scientists are finding carbamates and their transformation products in our drinking water.

Environmental Protection Agency (or EPA) has health standards for pesticides before being released into the environment, but environmental groups have repeatedly identified chemicals (e.g. chlorpyrifos) that pass EPA’s requirements mark but are later found to be toxic.

What Are the Risks to Human Health?

The effects of pesticides on the human body are as varied as the chemicals themselves. Organophosphates and carbamates, for example, affect the nervous system, while others irritate the eyes or skin. They can be carcinogenic or disrupt the body’s endocrine system.

Scientists are studying both the acute and chronic effects of ingesting pesticides. Pesticides are being detected at low concentrations, and as such, acute toxic effects (like nausea or chemical burns) are of less concern for most people. Farmworkers and landscapers directly applying herbicides and pesticides are likely most at risk (consider the evolving case of glyphosate).

Many are concerned, though, that these chemicals can accumulate over time, leading to greater health effects.

Are Pesticides in My Drinking Water?

Only small quantities of pesticides have shown up in treated drinking water. There are two directions of research, however, that promise to illuminate more about how pesticides impact drinking water: 1) cumulative exposures and 2) transformation products.

So far we have been writing about one chemical at a time. In reality, there are multiple herbicides and insecticides present in the environment. Health impacts of cumulative exposure to these compounds are not well understood, which means that our general assessments of risk are likely under-estimating the potential health impacts of pesticide exposures.

As we noted above, scientists have found the transformation products of pesticides in drinking water. A pesticide transformation product is a new chemical formed when the “parent” compound (e.g. DDT) reacts under different conditions – e.g. sunlight or bacteria in the environment or UV treatment in a water treatment facility. Sometimes, these transformation products are even moretoxic than the parent compound. Until engineers and scientists identify the multiple transformation products formed when chemicals enter our treatment systems, we can’t be sure that we are adequately treating our water.

Check out our water testing packages to make an informed decision about your drinking water or get in touch with us here for more information!










The Link Between Fluoride in Water and ADHD: Should You Be Concerned?

New Findings Suggest Fluoride Connected to An Increased Rate of ADHD in Children

Fluoride and ADHD.png

What is Fluoride?

All water contains some fluoride. Naturally occurring in water, soil, rocks ,and air, fluoride is a mineral also found in your bones and teeth. There have been numerous studies championing the benefits of fluoride on dental health and many U.S. water systems intentionally add fluoride to the drinking water supply.

While fluoride has been added to drinking water for upwards of 70 years in the United States, fluoride has come into the hot seat in recent years. A study published in the Journal Environmental Health found that areas with a higher proportion of artificially fluoridated water also had a higher prevalence of attention deficit hyperactivity disorder (ADHD) in children.

Additionally, a University of Toronto study suggests that higher levels of urinary fluoride during pregnancy are associated with an increase in ADHD-like symptoms in young children.

This begs the question: How concerned should you be about fluoride in drinking water?

What is Artificial Water Fluoridation?

Artificial water fluoridation is the practice of adding low concentrations of fluoride–0.7 parts per million (ppm)–to drinking water with the goal of improving dental health. Despite no legal mandate to fluoridate water, nearly 75% of the U.S. population of people had access to fluoridated water. It is widely considered to be a major factor in the 25% decrease in rates of tooth decay in the United States. While hailed as “one of public health’s greatest success stories” by some, the addition of fluoride to drinking water has always had its skeptics, and some people are downright opposed.

Does Fluoride Increase the Risk of ADHD?

For decades, health experts have disagreed as to whether artificially fluoridated water is toxic to the developing human brain. While extremely high levels can cause dental and skeletal fluorosis, it can also cause neurotoxicity in adults. Far less, however, is known about the impact on children's’ developing brains.  

What Does Research Suggest about the Risks of Fluoride?

Since a popular study on fluoride and neurodevelopment began in 1992, the percentage of the U.S. population that drinks fluoridated water has increased from 56 percent to nearly 70 percent. During that same time frame, the percentage of children with an ADHD diagnosis has increased from around seven percent to more than 11 percent.

Additionally, the 2018 University of Toronto study included the analysis of urine from women during pregnancy, as well as from their children from ages six to 12. Researchers examined how levels of fluoride in urine related to the children’s inattention and hyperactivity. After adjusting factors that impact neuro-development (such as gestational age at birth, birth-weight, birth order, sex, maternal marital status, smoking history, age at delivery, education, socioeconomic status and lead exposure), researchers were able to assign scores related to ADHD. They concluded that prenatal exposure to fluoride was associated with an increased frequency of inattentive behaviors and cognitive problems.

Finally, upwards of 40 studies show that children born in areas with elevated concentrations of fluoride (i.e. above the concentration typically used in U.S. public water system), have lower than average IQs. In fact, many studies demonstrate a significant link–showing that children in high fluoride areas had IQs that were seven points below those of children from areas of low concentrations of fluoride.

How Might Fluoride Increase the Prevalence of ADHD in Children?

The studies mentioned above suggest an association between fluoride and ADHD, however they do not prove causality. The question becomes, how might fluoride increase the prevalence of Attention-deficit/hyperactivity disorder? Below are some possible links:

Fluoride and Fluorosis:

Several studies suggest that children with moderate to severe fluorosis–i.e. The change in the appearance of tooth enamel due to excessive fluoride intake–can lead to a lower score on IQ tests and other measures of cognitive skills. According to a report by the Center for Disease Control  (CDC) suggests that 41% of Americans ages 12 to 15 have some form of fluorosis.

Fluoride and Lead Absorption:

The form of fluoride typically added to U.S. water supplies (fluorosilicic acid) can leach lead–a potent neurotoxin–from pipes. Research has shown that fluoride may increase the body’s ability to absorb lead and children in regions with highly fluoridated water frequently have elevated blood lead levels. Lead has been shown to play a role in ADHD.

Fluoride and Thyroid:

It’s been proven that fluoride impairs the activity of the thyroid gland, which is important for proper brain development.

Not Everyone Agrees on the Link Between Fluoride and ADHD

These findings have led many people to advocate against fluoride, however others were also eager to point out that this is just one study and may not definitively prove the causal link between fluoridation and ADHD. Limitations on the study include:

  1. Individual fluoride exposures were not measured

  2. ADHD diagnoses were not independently verified

  3. There may be other unknown factors (i.e. confounders) that explain the link

Should You Be Concerned About Fluoride in Drinking Water?

Despite the controversies surrounding artificial water fluoridation, the literature on the matter remains overwhelming positive. Fluoride is safe in low, controlled doses.

If you are concerned about your water quality (for any reason), Tap Score home water testing can help. Tap Score tests for fluoride, as well as 100s of other contaminants. For any questions, send us a message at hello@simplewater.us and our team f chemists, engineers, and water quality experts will be standing by!



























Are Microplastics in my Drinking Water?


Microplastics are in the environment and they are there to stay. 

Microplastics are tiny pieces of plastic, measuring less than five millimeters in length. That’s about the size of a sesame seed, and they can be as small as the period at the end of this sentence (or smaller). 

While you might be familiar with large plastic gyres in the ocean, a recent study suggests that most of the plastic waste in the ocean is not visible on the surface, but rather hidden as microplastics in the water and in marine life. 

An easily recognizable form of microplastics in our everyday life is microbeads–those tiny beads found in face washes and toothpaste. While those microbeads may make your teeth shine and your face shimmer, they’re ending up everywhere in our environment, including our drinking water.

In 2015, President Barack Obama banned microbeads in personal care products and other several countries followed suit. The problem, however, is far from over. Microplastics continue to end up in oceans, lakes, inside animals, and even in drinking water from other sources (like clothing).

Plastic doesn’t decompose or breakdown the way that organic matter does, so when large pieces of plastic degrade into smaller bits, they persist in the environment indefinitely. 

Almost all of the plastic ever manufactured is still on earth. And we're finding it in our drinking water.

Where do Microplastics Come From?

Much of what we manufacture and use (and a huge chunk of our waste) contains plastic. Microplastics come from tires rubbing against pavement, from synthetic clothes, and from paint dust floating through the air. 

Most microplastics are in the form of microfibers. A study commissioned by Patagonia© found that a single fleece coat can release up to 250,000 microfibers in one washing cycle

Are Microplastics in my Drinking Water?

The short answer? Probably, according to a recent study by the University of Minnesota School of Public Health and Orb media.

Plastic has long been a problem for ocean and lake ecosystems, leading to the emerging field of study on microplastics. Knowing how pervasive plastic is in our world and our waters, the question remains: are we drinking it too?

Researchers at the University of Minnesota and journalists at Orb sampled drinking water from metropolitan areas around the world. Overall, they found that 81 percent of samples contained microplastics. 

In the US alone, 94% percent of drinking water samples were found to contain microplastics.

Can Microplastics Affect My Health?

What is all this plastic in and around us doing for our health?

Studies have shown that plastic can absorb toxic chemicals in the environment and leach them out. Put simply, plastic can carry toxic chemicals and then release them later on, exposing people to harmful chemicals. This happens after people have ingested microplastics, but also from drinking bottled water that’s been left in the sun. Those toxic chemicals—such as bisphenol A (BPA) and di-(2-ethylhexyl)phthalate (DEHP), which can disrupt hormone levels — can stay in your gut or move to affect other tissues.

Research has shown that microplastics can also be a vehicle for pollutants such as metals and dioxins, which can cause reproductive and developmental problems.

As plastics break down into smaller and smaller particles, they can infiltrate into tissues, making their way into the bloodstream. Most research has been conducted on the effects of ingesting plastic in wildlife populations, but similar research is beginning with humans.

As microplastics are a relatively recent field of study, the effects of microplastics on human health remain largely unknown.

What Can I Do?

While we don't yet know what the health impacts really are, there are a few ways you can filter your water that will likely remove microplastics:

1) Carbon filter

2) Reverse osmosis 

3) Ion exchange 

In selecting a treatment technology, check the pore-size. Microplastics in the Orb study were about 2.5 microns. A filter with a pore size less than 2.5 microns will remove most microplastics from your tap water. 

Don't hesitate to get in touch if you would like more suggestions, or if you want to test your water for microplastics to learn more. 














Lithium on the Brain – or in Your Water?


Small amounts of lithium could have huge impacts–or so some suggest.

Should we all be Drinking Lithium in our Water?

The potential benefits of small traces of lithium could be huge, however not that many people are talking about it. While we usually talk about contaminants negatively impacting your health if we find it in drinking water – lithium is a rare example of an element that may actually benefit your health. How is that so?

In this post, we’ll cover what Lithium is, how you might be exposed through drinking water, and what scientists hypothesize the potential benefits could be.

What is Lithium and How am I exposed?

Lithium is a natural metal that appears in rocks, soils, groundwater, surface water and freshwater. Ubiquitous in nature, Lithium is commonly found in plants, animals, foods, beverages and drinking water. Most of our exposure to lithium is through our food, but drinking water contributes about one fourth to our exposure to lithium.  There are no major health concerns associated with lithium, and no public health regulations for lithium in drinking water.

How does Lithium Affect My Health?

Lithium has a long history of proposed medical benefits. Starting back a few thousand of years ago, lithium was discovered in mineral springs and recognized for its healing properties. The most famous being spring was known as the Lithia Springs, thought to have healing powers that attracted big names like Mark Twain and four U.S. presidents including Theodore Roosevelt hoping to reap the benefits.

In the mid-20th century, medical professionals began to experiment with using lithium as medication for mental illnesses including bipolar disorder and depression. It is now a widely used drug with life saving impacts.

Scientists have wondered: could exposure to low doses of lithium benefit society writ large?

What’s the State of the Research?

A Brief Review of Studies Linking Lithium in Drinking Water and Health Outcomes 

A review of the available literature connecting lithium in drinking water and suicide prevention indicates that “higher lithium levels in drinking water may be associated with reduced risk of suicide in the general population”.

The “may” is operative here – research isn’t completely clear yet on the impacts of being exposed to lithium, though the shared hypothesis of many studies is that it is a positive benefit.

Texas Study

The positive correlation between small amounts of lithium and improved mental cognition was proposed in a 2013 study in Texas which found that “lithium levels in the public water supply were negatively associated with suicide rates in most statistical analyses”. The study, however, was criticized for lack of statistical analysis. Researchers largely left the topic alone until recently.

Denmark Study

nationwide study in Denmark involving 73,731 patients with dementia and 733,653 control individuals concluded that “long-term increased lithium exposure in drinking water may be associated with a lower incidence of dementia”.  However, while the study found that the population receiving over 10 micrograms of lithium in drinking water had a 17 percent decrease in dementia, the population receiving between 5.1 - 10 micrograms of lithium in actually increased in likelihood of incidences of dementia by 22 percent. This suggests that there is some ambivalence over the impact of lithium exposure depending on the amount people are exposed to.

Lithuania Study

A study examining “the relationship between lithium levels in drinking water and suicide rates in Lithuania”, found that between the years 2009-2013 there was a statistically significant correlation between higher levels of lithium in drinking water and lower suicide rates – but only in men only.  

Japan Study

Another study in Japan indicated “that natural levels of lithium in drinking water might have a protective effect on the risk of suicide among females”.

Proposed Medical Benefits of Lithium

Lithium is prescribed as a medication for mental illnesses such as: bipolar disorder, depression, and schizophrenia. Prescription doses are at levels which are 50-600 times more than the average daily intake from food and far more than then the normal exposure of lithium through drinking water.  Very small levels over long periods of time are hypothesized to potentially promote brain health, which could decrease the rate of mental illnesses and suicides – which is the 10th leading cause of death in the United States.

How Might Lithium Improve Cognition?

The mechanism by which lithium affects your brain is unknown. Some suggest that lithium increases the activity of chemical messengers in the brain. Another possibility is that “lithium exposure, even in these tiny amounts, might actually be neuroprotective or even enhance the growth of neurons”.  

Don’t put Lithium in Drinking Water Just Yet

While studies are finding that trace amounts of lithium in drinking water might benefit our mental health, all studies indicate the need for further research and the potential for other factors impacting the results.  

We also receive on average more lithium from our food than from our drinking water, but diet is hard to measure in large studies, therefore it is difficult to understand its impact.  Lithium can also be lethal at high and even potentially lethal at low doses.

While research is promising, the actual mechanisms behind lithium's impact on the brain are still debated – so it's best not to jump to any conclusions and alter our water supply with added lithium!


Send any concerns or inquiries to Tap Score and you’ll be connected to a water quality expert in no time – hello@simplewater.us.










Risks of Distilled Water


What is Distilled Water?

Distilled water is a type of purified water that has been boiled until it evaporates. The water vapor is then condensed back into liquid form, leaving the water devoid of impurities.

At first glance this sounds great. However, “impurities” don’t just include the unwanted things in your water. The term covers a wide range of dissolved and suspended solids–from contaminants to minerals. While yes, we all want our water contaminant-free, the distillation process is non-discriminatory removal process that strips water of the good and the bad.

This leaves some arguing that as a suitable drinking water choice, distilled water leaves somethings to be desired.

Potential Health Risks of Drinking Distilled Water

According to the World Health Organization report, there are a handful possible negative effects that come with drinking demineralized (i.e. distilled) water–WHO claims it “might not be fully appropriate for consumption” because distilled water:

  1. Can cause metals and other materials to leach from pipes and storage containers

  2. It doesn’t taste as good as tap water

  3. Can lead to low intake of essential elements and micronutrients

We’re going to breakdown these concerns below. The main point is this: while distilled water is better than contaminated water, it is not better than regular tap water and may even have negative health impacts.

Why does distilled water cause pipes and storage containers to leach undesirable contaminants?

If you store distilled water for drinking, you may be at risk of consuming parts of the container you store the water in. Because low- or demineralized water is molecularly unstable, it is “highly aggressive” to materials with which it contacts. Subsequently, distilled water can leach undesirable compounds from any material it comes in contact with.

Distilled water more readily dissolves plastics, (heavy) metals, and some organic substances from pipes, coatings, storage tanks and containers. As a result, you may wind up consuming them instead.

If you do drink distilled water, we recommend that you store it in glass.

Why does distilled water taste worse than regular tap water?

It is often reported that distilled water doesn’t taste as good as tap water. Some even claim it is less thirst quenching.

Why? Isn’t it just water?

When distilled water is created through the boiling process, the dissolved air within leaves the water. Subsequently, this results in a flat taste. Additionally, along with the loss of the dissolved air, calcium is also eliminated–which, when present, often contributes to water’s pleasant taste.

While neither flat taste nor lack of thirst-quenching are considered to be health effects, they could have some very real implications–as it may affect the amount of water one drinks.

How does distilled water impact nutrient intake?

While regular tap water is generally not a major source of nutrients, its contribution may be significant to your health–particularly when it comes to calcium and magnesium. As a World Health Organization (WHO) report notes, the typical modern diet may provide inadequate amounts of minerals and microelements. Subsequently, if faced with borderline deficiency of particular element, the relatively low intake of the element from drinking water may play a protective role in your health.

Elements in drinking water are usually present as free ions (rather than being bound to other substances when in food), making them more readily absorbed in the body.

In fact, the same WHO report goes on to discuss a handful of epidemiological studies from the past half century that indicate that water low in calcium and magnesium (also known as ‘soft water’) is associated with the following (when compared to hard water):

  1. Increased morbidity and mortality from cardiovascular disease

  2. A higher risk of fracture in children

  3. Certain neurodegenerative diseases

  4. Preterm birth and low weight at birth

What are the Uses of Distilled Water?

While we don’t typically recommend drinking distilled water, it certainly has its merits. Distilled water is often used for in laboratories for experiments, as well as for a variety of industrial applications. It is also a good choice for humidifiers, aquariums, and for use in cooling systems (as many many minerals found in tap water can damage lead-acid batteries).

What it Boils Down To

While we (generally) recommend drinking tap water over distilled water, this only holds true if you know what’s flowing from your tap. You should always test your water before making a definitive decision as to what is the best choice for you. If you find that  you have low-quality or contaminated tap water, then distilled water is a better (and safer) choice

Check our our water testing packages to make an informed decision or send us a message at hello@simplewater.us for more information!