Emerging Water Contaminants - What you Need to Know
One downside of new inventions and innovations is the possibility of generating materials that could be harmful to the environment. As our technologies improve over the years we’ve been made aware of this. Aside from that, we’ve also realized that some of the materials circulating in the market have the potential to contaminate our environment. In this article, we shall focus on emerging water contaminants; materials that are synthesized just recently and have the potential to contaminate our waters or materials which have been invented in the past but whose hazards were only found out recently.
The realization that the process of water disinfection could inadvertently generate pollutants in the water came in the 1970s when T.A. Bellar noticed that chloroform was absent in the Ohio River but was present in the plants that disinfect the water from the said river. Since then, authorities and the scientific community have been tackling this problem.
Disinfection byproducts are strictly chemicals, be it organic or inorganic, that are formed when disinfectants like chlorine react with other chemicals that are naturally present in the water being treated by it. Humic acid and fulvic acid are chemicals that are naturally present in water that may react with chlorine when the water is being treated. These two chemicals come from the decomposition of plant matter.
This disinfection byproduct is considered carcinogenic and may be damaging to the liver, kidneys, and central nervous system
Halogenic acetic acids
Halogenic acetic acids is a chemical group that could increase people’s risk of cancer
This chemical can damage the gastrointestinal tissues when ingested which makes this disinfection byproduct all the more dangerous.
Although it may not occur all the time, chloropicrin can breakdown and release toxic gases including carbon monoxide, nitrogen oxides, chlorine, nitrosyl chloride, and phosgene.
There have been incidents where people have been exposed to large quantities of chlorophenols. In one of these incidents, a man who worked on a pesticide factory accidentally splashed his arm and leg with a large quantity of pure 2,4-dichlorophenol. This resulted in his death just minutes after.
Although it may take high levels of chlorophenols for adverse effects to develop. Who knows what this chemical could do to the body if it is exposed to it chronically even at low levels. In animal studies, chlorophenols had negative effects on the test animals’ liver and immune system. This may have the same effect on humans too.
Cardiac arrhythmia is a known toxic effect of acute chlorohydrates poisoning. Exposure to lower levels of Chlorohydrates can cause central nervous system depression. This effect of chlorohydrates is the reason why they are used as medicine. However, chlorohydrates may have some tumor-promoting effects. In animal studies, researchers reported that chlorohydrates can encourage the growth of tumors in the liver of mice.
The effects of haloketons on humans are unknown. Researchers conducted studies on mice and discovered that this chemical can cause tumors in their skin.
This chemical is used as a sedative for children with whooping cough. There were instances wherein children died due to accidental overdose of the chemical. So if the drinking water would be contaminated with high amounts of bromoform it may lead to death. However, it is highly unlikely that the level of bromoform in the drinking water would reach a point wherein this would be possible. Nonetheless, animal studies have shown that even small but chronic exposure to bromoform can lead to kidney damage.
Chlorine dioxide and chlorite when they come into contact with your mouth, esophagus, and stomach may cause irritation in sufficient amounts. When our tap would have so much chorite, drinking it may irritate our gastrointestinal lining. Aside from that, showers may generate aerosols that contain a lot of this chemical which may irritate the respiratory lining when inhaled.
Most research on chlorite focused on its negative effect on people’s blood. Several animal studies have shown that when chlorite is absorbed by the gut and introduced into the bloodstream, the chemical could induce methemoglobinemia.
Nitrite and Nitrate
Adults aren’t affected by nitrate or nitrite that much. However, young infants, ages 6 months and below are sensitive to these chemicals. The worse thing is, exposure to these chemicals can occur when the water used for formula milk is contaminated with nitrate or nitrite. In most cases, it is the bacterial contamination that is indicated by the nitrite or nitrate that causes adverse effects to those who would drink water that is contaminated with the said chemical. However, there are instances where there were unusually high levels of nitrite and nitrate in water, and that the chemicals themselves caused blood pressure and heart rate spikes, reduction of the oxygen-carrying capacity of blood leading to hypoxia, headaches, abdominal cramps, vomiting, and even death.
Hydrazine is a corrosive liquid that can cause chemical burns and severe dermatitis. It may cause irritation to the eyes when the eyes are accidentally exposed, it could even cause temporary blindness. When inhaled it could irritate the nose and throat. When ingested it may cause dizziness, headaches, nausea, pulmonary edema, seizures, and even coma.
Most bromate poisonings are caused by the ingestion of sodium bromate and potassium bromate. The majority of these bromate poisonings resulted from the deliberate ingestion of permanent wave kit neutralizers. Symptoms of bromate poisoning include anemia, hemolysis, renal disease, and hearing problems. The most common symptom seems to be hearing problems in both adults and children. Bromate poisoning becomes fatal when the dose exceeds 6 grams.
Underbromic acids include hydrobromic acid and hydrogen bromide, they can come in gas form or in aqueous form. Both forms can irritate the eyes and cause teariness. Underbromic acids can damage the eyes, mouth, throat, gastrointestinal system, and even the respiratory tract. However, underbromic acids contamination in our water system wouldn’t reach a concentration that could damage the aforementioned organs or organ systems.
Although there are some research papers that showed hydrogen bromide isn’t carcinogenic, there aren’t enough studies to rule out the possibility that frequent low-level exposure to underbromic acids can lead to negative health effects.
The toxicological properties of alkanic acids aren't well studied yet. However, at high enough concentrations it could cause irritation to the eye, skin, and respiratory system. This chemical may be harmful if it is inhaled, ingested, or absorbed by the skin in sufficient amounts.
By now, a lot of people are aware of the health hazards of benzene. Long-term exposure of the skin to low levels of benzene can lead to dermatitis. Once this chemical enters the body, it can be life-threatening. Benzene can lead to anemia. Aside from that, it could also decrease the number of white blood cells and platelets which could harm the clotting function of the blood and its immune function. A person who has benzene circulating within their body will yield abnormal results in their blood tests. There are some studies that indicated that benzene can harm the nervous system but further studies are required. It is clear that Benzene is a carcinogen, several studies have indicated this. Benzene can cause cellular abnormalities in the blood leading to cancer of the blood, either leukemia, lymphoma, or myeloma.
Pesticides and biocides
Perfluorooctane sulfonates (PFOS)
Around 2 decades ago, countries agreed to collaborate on gathering information relating to the environmental hazards and health hazards of perfluorooctane sulfonates. Due to this, it was discovered sooner that this chemical is damaging to both the environment and to human health. In 2001, the company ‘3M’ one of several major producers of PFOS decided to stop the manufacturing of this chemical.
In December 2000, a draft of the hazard assessment of PFOS was created. In 2001, several countries gathered to discuss the draft for finalization, taking into account information gathered from newly published studies. In November 2002, a final draft was created, assessed, and endorsed.
It is clear that PFOS is a chemical that stays inside the human body for a prolonged period of time, exhibits bioaccumulation or increases in concentration as we move up the food chain, and harmful for mammalian species. The PFOS persistence in a mammal’s body varies from species to species. This was made evident by some studies which used varying test animals. For rats, it took 100 days for the PFOS to be completely removed from their bodies and 200 days in monkeys. For humans, it may take years for the PFOS to be completely eliminated. Due to this property, PFOS is even more dangerous especially when the exposure is chronic. In animal studies, exposure to PFOS results in liver damage which may lead to liver cancer. Aside from that, it could also damage the thyroid which leads to thyroid cancer. There are some human studies that showed a correlation between the increase in bladder cancer incidence and PFOS exposure. However, more studies are required to strengthen this association.
Before PFOS was phased out, several household products contained PFOS. When these household products get carried away through the drain and mixed with wastewater, the PFOS contaminated water may end up in rivers, oceans, and other bodies of water. Facilities that produce products that use PFOS could also release wastewater that contains high amounts of PFOS in bodies of water. Marine life in these PFOS contaminated bodies of water may absorb the chemical. Bioaccumulation could occur when a large number of animals at the bottom of the food chain absorb the PFOS. Animals a step above in the food chain could consume a number of PFOS contaminated animals and amplify or accumulate the amount of PFOS. As we go up the food chain, the amount of PFOS increases exponentially. This can occur with humans and fish. Certain fishes could consume tiny marine animals that could absorb the PFOS and accumulate it. When humans consume fish, it would contain a tremendous amount of PFOS.
Perfluorooctanoic acid (PFOA)
This chemical is a byproduct of the production of fluoropolymers. The latter chemical has several industrial applications most notably in the manufacturing of products that are heat, oil, stain, grease, and water-resistant. PFOA is a polymer that can’t be broken down by natural decomposition processes which is why it could persist in the environment for a long time. Similar to PFOS, they can be absorbed by animals and bioaccumulate.
It is evident that PFOA can contaminate water. Exposure to PFOA can come from drinking this contaminated water. Most of the time, PFOA contamination in drinking water is low. Although the effects of low-level PFOA exposure are unknown, this chemical can remain in the human body for a long period of time and thus can accumulate. At sufficient concentrations, PFOA can hamper growth and development, damage the reproductive organs, and damage the liver. So far these are the possible health effects of PFOA based on existing studies. However, more research studies are needed to fully understand how this chemical behaves within the body and which organs it could potentially damage.
Pharmaceutical and Personal Care Products (PPCPs)
Chemicals involved in the production of Pharmaceutical and Personal Care Products include antibiotics, anti-inflammatory drugs, hormones, cytostatic drugs, contrast media, β-blockers, blood lipid regulators, antiepileptic drugs, antimicrobials, ultra-violet filters, preservatives, insect repellents, synthetic musks, and more. Improper disposal of these drugs or chemicals can lead to the contamination and accumulation of the said chemicals in bodies of water and even plants. The realization that these drugs and chemicals can contaminate the environment came recently as researchers have detected low concentrations of these chemicals in the environment.
PPCP contamination of water is often done unintentionally. In the agricultural sector, antibiotics can be given to livestock as feed. These feeds could fall to the ground and get carried off by water when the animals’ pens are cleaned. The animals’ wastes could also contain residues of the antibiotics given previously which could also get carried off by water. At this point, the antibiotic-contaminated water could contaminate bodies of water in various ways. One way would be that the antibiotic-contaminated wastewater would be treated by treatment plants but cannot effectively remove the antibiotics. Thus, when the treatment plant releases the water into the environment, it would still contain a significant amount of antibiotics. In the home setting, people could also inadvertently contribute to PPCP contamination. Flushing drugs down the toilet could introduce drugs into the wastewater. Insect repellants and certain perfumes are considered as PPCPs and could contaminate our water when they are used and then washed off by bathing. People who take certain kinds of drugs would excrete byproducts of the drug in their urine. These instances could lead to the contamination and possible accumulation of PPCPs in wastewater which could lead to environmental contamination.
Studies have shown that instances of PPCP contamination involve low-levels of their chemicals. Yet other studies have shown that PPCP chemicals may affect animals greatly despite being exposed to low levels of PPCP drugs and chemicals. Furthermore, researchers have detected PPCPs in aquatic organisms and they’ve also shown that humans can get exposed through drinking water. Since PPCP drugs and chemicals were recovered from aquatic organisms, soon after researchers realized that PPCP can accumulate in aquatic organisms that humans consume such as fish. With that realization, researchers did recover the chemicals and drugs found in PPCPs in fish.
Antibiotics accumulating in bodies of water even in wastewater may pose a serious problem. Pathogenic bacteria present in these bodies of water may become resistant to the drugs accumulating in the bodies of water. This may lead to the development of bacterial strains that are resistant to drugs that are used to treat the diseases that they would cause.
Steroids and Endocrine-disruptors
The endocrine system is the organ system composed of several glands that communicate with each other through hormones to maintain balance within the body. However, certain chemicals both natural and man-made can disrupt this organ system and throw the body out of balance which could lead to diseases. These chemicals have been categorized as endocrine-disruptors. Unfortunately, they are quite common and can be found in various everyday products such as plastic bottles, containers, food cans, flame retardants, toys, pesticides, cosmetics, and even certain processed foods. Furthermore, some endocrine-disrupting chemicals can’t be broken down easily by natural processes and would persist in the environment making them potentially hazardous.
There are ongoing studies about endocrine-disrupting chemicals. Studies conducted on animals have uncovered negative health effects on the test animals. However, the negative health effects of endocrine disruptors on humans are still uncertain. The fact that endocrine-disruptors are present in various items makes it harder to study its negative effects on humans, for it is difficult to control or measure a person’s exposure to endocrine-disrupting chemicals.
So far these are the known endocrine-disrupting chemicals:
Bisphenol A (BPA)
These are found in plastic products like food storage containers. BPA is used to make polycarbonate plastic and epoxy resins which are needed to make various plastic products.
Dioxin is involved in herbicide production and paper bleaching. When herbicides containing dioxins are used on certain plants they would release the dioxins when they are burned. The same thing would happen if paper products that are bleached with herbicides are burned.
This chemical is used in the aerospace industry, weapon production, and the creation of pharmaceutical products. Unfortunately, using this chemical in the production of certain products led to the contamination of drinking water. Exposure can come from fireworks as well for perchlorate is used in their production.
The reason why certain plastics are more flexible is because of this chemical. Any product that is made up of flexible plastics like food packaging, cosmetics, children’s toys, and medical devices could potentially contain phthalates.
Naturally occurring substances in plants that have hormone-like activity, such as genistein and daidzein that are in soy products, like tofu or soy milk.
Polychlorinated biphenyls (PCB)
Used to make electrical equipment like transformers, and hydraulic fluids, heat transfer fluids, lubricants, and plasticizers.
This chemical may be found in some anti-microbial and personal care products like liquid body wash.
Flame retardants and their impurities
Polybromonated diphenyl ethers or PBDEs
This group of chemicals has been utilized since the 1960s. They are used as additives to products so that the product can become resistant to flames. Despite being a beneficial chemical for the prevention of fires, PBDEs are harmful to both humans and the environment. Researchers have recovered PBDEs in coastal and estuarine environments. Aside from that PBDEs were also detected in air, soil, sediments, wildlife, fish and other marine life, sewage treatment plant biosolids, and even in humans. PBDEs are found contaminating the environment because of the fact that manufacturers are releasing the chemical into the environment and common household products containing the chemical are indiscriminately littered. The extent of how household products could contribute to PBDE pollution is still unknown. There are concerns that improper disposal of household products containing PBDEs can lead to the release of brominated dioxins and furans which are dangerous even at minute doses.
Researchers have demonstrated that PBDEs have bioaccumulative and biomagnification properties. Furthermore, PBDEs were recovered directly from human blood, serum, adipose tissue, breast milk, placental tissue, and brain. These points to the idea that human exposure to PBDEs can come from the consumption of contaminated fish. Other ways of exposure include consumption of contaminated poultry, meat, and dairy products, inhalation and dermal absorption, and occupational exposure such as in computer and electronic warehouses.
HBCDs are a group of chemical flame retardants which are utilized in the production of thermal insulation in building materials, and flame-resistant upholstery textiles and electronics. The widespread usage of HBCDs and the products that contain this chemical resulted in the pervasive presence of HBCDs in the environment.
HBCDs were detected at high levels near point sources. In other words, HBCD contamination is higher in areas near production facilities. Conversely, areas far away from HBCD production facilities have lower levels of HBCDs. When HBCD concentrations were compared between predators and prey, animals that are found higher in the food chain contained more HBCDs. Meaning that HBCD may have some biomagnification properties. In studies that measured HBCDs in humans, concentrations of the chemicals were relatively low, on average 0.35 to 1.1 nanogram per gram lipid weight. Longitudinal studies on the HBCD levels in various plants and animals have shown that the rising levels of the chemical reflect its increased demand and usage.
Nanotechnology is utilized in various industries including medicine, agriculture, engineering, and more. The advancement of nanotechnology has inadvertently created a problem, the liberation of ultrafine nanoparticles which have been recently regarded as a health hazard. Ultra-fine particles and coatings are the most common nanotechnology products circulating in the market. They are utilized in various applications and can be found in products like textiles, self-cleaning glass, and sunscreens. As nanotechnology improves, researchers believe that more products would contain ultra-fine particles. Thus, The Project on Emerging Technologies, which is based at the Woodrow Wilson International Center for Scholars, created a list to monitor this growing list of nanotechnology products. In 2005, the project’s research team was able to list 1628 consumer products that contain nanoparticles.
There are currently no definitive studies that demonstrate the negative health effects of nanoparticles. Despite this, they are potentially dangerous due to various reasons:
Ultrafine particles from diesel machines, power plants, and incinerators can cause harm to the human lungs. Due to their minute size, they can’t be filtered by our respiratory system and go deep into the lungs. Since these particles can carry chemicals like metals and hydrocarbons, they can do considerable damage once they would reach the lungs. The same thing could happen with nanoparticles. They may carry chemicals into the lungs by bypassing our respiratory system’s filters.
There are concerns that nanoparticles may introduce free radicals into our cells. They can easily go through the skin, lungs, and digestive system. Which means they can introduce free radicals into the cells in these organ systems. Furthermore, they may be able to enter the bloodstream and cross the blood-brain barrier which may cause damage to the brain.
Nanoparticles are materials synthetically created which means they only appeared now and haven’t been around for a long time. This means that the human body hasn’t adapted to this new material and would likely react to this material negatively.
As mentioned earlier, currently, there are no studies that clearly demonstrate the negative health effects of nanoparticles. However, there are ongoing studies with compelling evidence that seems to support their supposed effects:
Several animal studies involving rats demonstrated that nanoparticles can cause lung damage in them. In these studies, they focused on carbon nanotubes which are ultrafine particles that are similar in shape to the asbestos fibers. The test animals developed mesothelioma, which is a kind of malignant cancer in the lungs that are caused by the inhalation of asbestos fibers.
A study conducted in Germany showed that ultrafine particles were able to enter the brain of rodents. The particles entered the nasal region of the animal and traveled up the olfactory nerves and into the brain bypassing the blood-brain barrier.
Inhaled carbon nanotubes can negatively affect T cells which is a type of white blood cell responsible for coordinating the immune system. Thus, inhaled nanotubes may be able to suppress the immune system.