We also need clean water with which to wash viruses, bacteria and chemicals from our food and from our skin. And yet, around over 1 billion people do not have access to improved drinking water sources and around 2.4 billion people lack adequate sanitation. Four-fifths of all illnesses in developing countries are from waterborne diseases .
The World Health Organization estimates waterborne diseases cause two million deaths annually, mostly of young children . And these diseases, manifesting in diarrhea and infections are only the more obvious illnesses caused by water pollution. Cancers from chemicals, like mercury falling in acid rain, or neurological problems from pesticides in agricultural runoff or lead leaching through the soil into the groundwater from a smelter, chemicals that poison marine life and make their way up the food chain are less easy to pinpoint as caused by polluted water.
Water can become polluted by deliberate direct dumping of garbage or animal carcasses, accidents like oil spills, or indirectly from storm drainage, runoff from polluted soils, pollution leaching through the soil and into the groundwater or even by rain bringing down the particulate matter in the atmosphere from industrial processes and the burning of fossil fuels.
Waterborne diseases are caused by drinking water or eating food washed in water containing protozoa that can cause infections like toxoplasmosis or giardiasis, containing viruses like polio or Hepatitis A, water with bacteria like E.coli, cholera or typhoid fever or water with parasites like hookworm and ringworm.
Waterborne diseases are generally from human or animal waste in the water. The most common waterborne diseases in North America are from one of two microscopic parasites found in human feces that then contaminate water: Cryptosporidium and Giardia. They each can cause severe abdominal cramps, nausea, headaches, gas and fever, chills and vomiting .
Legionnaires disease, swimmer’s ear, SARS (Sever acute respiratory syndrome), polio, botulism – these are all diseases we are familiar with and they are all waterborne diseases. The most common waterborne diseases in developing countries lacking adequate supplies of clean water for drinking, washing food and personal hygiene include dysentery, typhoid fever, cholera and Hepatitis A .
Dysentery causes inflammation of the intestines, severe abdominal pains and diarrhea, often with blood.
The intestinal lining can be compromised, impairing nutrient absorption, causing bleeding, allowing bacterial infections and even the exit of pathogens into the bloodstream. Entire armies have been taken down by dysentery .
Typhoid fever is a life-threatening illness one can contract by eating food handled by a person shedding the Salmonella Typhi bacteria or by eating food washed with water contaminated by sewage with the Salmonella Typhi bacteria. Once ingested, the bacteria multiply in the bloodstream.
Symptoms include a very high fever, stomach pains, headache, extreme fatigue, joint pain and loss of appetite .
Sometimes, too, a rash will spread across the abdomen known as rose spots .
Cholera is an acute, diarrheal illness caused by infection of the intestine with the bacterium Vibrio. Cholera is rare in the United States but globally, cholera cases have increase steadily since 2005.
Epidemics are generally related to fecal contamination of water supplies or street vended foods.
Severe cases may cause profuse watery diarrhea, vomiting, and leg cramps. The rapid loss of body fluids can lead to dehydration and shock and without treatment, death can occur within hours .
Hepatitis A is a liver disease caused by the hepatitis A virus. The virus enters the water via the feces of an infected person. This can happen through broken pipes or by sewage overflows.
Accordingly, the virus can spread through water used to wash food. Too, a person living in the same household where personal hygiene is poor can contract Hepatitis A by putting something in her mouth that has been contaminated with the feces of the ill person.
Hepatitis A typically causes by fever, vomiting, stomach pain, jaundice or yellowing of the skin and eyes, dark urine, and fatigue .
When there is not an adequate supply of clean water for washing, eye and skin infections can easily occur and be very difficult to clear.
Trachoma is responsible for the visual impairment or blindness of nearly two million people in the poorest, most rural areas of Africa, Central and South America, Asia, Australia and the Middle East. Women and children are the most vulnerable populations.
It is an infectious disease, spreading through personal contact and by flies that have been in contact with the discharge form the eyes or nose of the infected person .
Yaws is a poverty-related bacterial skin infection that can severely disfigure children as well as affect their bones and cartilage.
It is prevalent in tropical communities with poor sanitation where it spreads through skin-to-skin contact and enters the body through a cut or scrape .
Scabies is an itchy skin condition caused by a tiny burrowing mite.
It is contagious and spreads quickly through close physical contact . It can be difficult if not impossible to get rid of scabies without washing bed linens and towels in hot, clean soapy water.
Shigellas is another infectious disease that can spread from an infected person to contaminate water or food.
Shigellas and the E.coli bacteria are the most common cause of traveler’s diarrhea, often from eating salad or sandwiches that have involved hand contact by someone who has picked up the bacteria from feces or feces-contaminated water and not washed their hands properly .
Water-based diseases are spread by organisms that develop in water.
The most common is schistosomiasis, or blood flukes, a parasite that hatches from eggs in the feces or urine of infected persons who defecate or urinate in freshwater in the tropics.
About two hundred million people are infected.
When the eggs hatch, the blood fluke parasite grows and multiplies inside snails. When they leave the snails, the parasites can penetrate the skin of persons who are wading, swimming, bathing, or washing in contaminated water.
The wormy parasite lives within the blood vessels of the human host, where the female produces eggs. The eggs then generally travel to the intestine, liver or bladder.
It is the body’s reaction to the eggs, not the worms themselves that cost a host of problems, including anemia, malnutrition, learning problems and over time, damage to the intestines, liver, bladder and even to the lungs.
Eggs have also been found in the spinal cord or brain where they can cause inflammation, seizures or even paralysis .
Other water-related conditions
Polluted water can be a factor for water-related vector-borne diseases, that is, diseases carried by mosquitoes or other insects who find favorable breeding grounds in polluted waters and multiply more rapidly. These insects then act as hosts for parasites and cause many serious diseases.
The primary vector-borne diseases are all serious and include:
- Filariasis (parasitic worms)
- Japanese encephalitis
- Yellow fever
- Dengue fever 
Malaria kills an estimated 1.2 to 2.7 million people per year. Mosquitoes and other water-related vectors (insects) reproduce in or near water, spreading these diseases. The contraction of these diseases is not related to water supply quality.
Health problems caused by chemical pollution of our water bodies
There are many ways that water can become polluted. Some of the most common ways include: direct disposal of waste into water bodies, contamination from land sources where the pollutants leak into groundwater, runoff from agricultural and urban landscapes, animal waste that harbors pathogens, and through acid rain (air pollutants such as mercury precipitate down into water bodies when it rains).
Water-polluting chemicals can be natural or manmade. Even if they are not obviously detected by our senses, they may still be present in water.
Common chemical pollutants usually originate from:
Agricultural runoff and eutrophication
Each year agribusiness sprays two million tons of pesticides, insecticides, herbicides and fungicides on crops . The dust is carried in the air, falling to the soil where it will. It washes off the plants. It contaminates soil through plant roots. And it is absorbed into the ground where it is sprayed. What the ground does absorb percolates down to the water table the nearby community accesses for water or it flows through the rock cracks to the nearest water source.
The soil ecosystem is usually so compromised from these chemicals that it no longer has the ability to absorb much rainwater, so when it rains, the chemicals wash across the surface to the next wetland, stream or river.
Certain types of algae can produce toxins and can reproduce in the presence of nitrates and phosphorous (such as from agricultural-sourced runoff) in water, producing “red tides” and “brown tides” that can harm and kill organisms such as fish, birds, and humans. When water is polluted with these toxic algae, the oxygen content is depleted, and has been known to kill fish. The toxins produced by these algae can also become airborne, and drift by the air and negatively affect the health of people who are living near the beach.
Presently, seven counties along the coastline of Florida are under a “state of emergency” due to the smelly, toxic algal bloom, known there as the red tide for its brownish-red coloring of the water. The algae, a single-cell organism Karenia brevis, produces chemicals that damage the central nervous system of fish.
This year the bloom has poisoned an estimated 267 tons of fish, manatees, sea turtles and other marine life and shows no sign of abating. Carcasses litter the beaches.
The waves crashing against the beach release the toxic chemicals into the air, causing residents to suffer serious respiratory problems .
Read The Main Causes of Land Pollution for a more in-depth discussion of the algal bloom created by excess nitrogen in the water and consequent dead zones as well as industrial waste from mining and other industries percolating through the soil and into water supplies.
Agribusiness is not the only industry contributing to water pollution. Every industry generating power and manufacturing the consumer goods we demand emits some particulates into the air which eventually fall to the earth and absorb into the water and many industries discharge contaminates into the water. These emissions and discharges are regulated in the United States, requiring the best available control technologies be utilized, but that is not to say that 100 percent of the emissions are contained.
And while the EPA may deem the emissions a “safe” amount per facility, one must add up all of the emissions from all of the industries that make it into the water.
Tens of thousands of chemicals are used in industrial processes including:
- chlorinated solvents
- MBTE, a gasoline additive to help it burn cleaner
- petroleum chemicals
- persistent organic pollutants
Persistent organic pollutants (POPs) are defined by the US Environmental Protection Agency as toxic chemicals that adversely affect human health and the environment around the world. They are labeled persistent because they do not degrade, but persist in the environment, they are transported by wind and water and affect life far from where they are initially released and they accumulate and pass from one species to the next through the food chain .
An accumulation of toxic chemicals can damage the liver, kidneys, cause reproductive and endocrine damage, neurological problems and thyroid disorders, as well as various cancers .
Of particular concern perhaps because they are easier to isolate are situations where water contains lead or arsenic. The World Health Organization has found that children are especially vulnerable to the irreversible effects of lead poisoning, which can cause a multitude of serious health problems, including severe damage to the neurological system and major organs.
In the United States recently, the federal government called a state of emergency in Flint, Michigan due to widespread lead poisoning of the community from the improper treatment of water from the Flint River causing lead to leach into the water supply .
The following table gives examples of health problems that can occur from chemical water pollution:
Nuclear waste leaching
Sometimes too, as in nuclear power plants, apart from accidents which do happen and cause serious water pollution problems from uranium, one of the most toxic chemicals known, hot water is discharged into nearby water, altering the marine ecosystem.
Improper radioactive waste disposal from uranium mines discharging into the ocean  to closed plants discharging into steams subject to water filtration system that have the ability to filter uranium, but nowhere to dispose of it
And while concentrations have been found to be very low, studies have shown adverse effects of the reproductive abilities of zebra fish exposed to them and no studies exist for the accumulation of small doses over many years .
Not all chemical pollutants are due to human contribution. An estimated 43,000 people in Bangladesh die each year from exposure to water containing naturally-occurring arsenic.
It is further estimated that between one and five million of children born between 2000 and 2030 will eventually die from cancer, cardiovascular disease or lung disease from drinking water laced with arsenic if the government does not take action to treat water supplies .
Why are waterborne diseases from raw sewage so prevalent in the US?
Why do 3.5 million Americans get sick with everything from ear infections to colds to diarrhea to parasitic infections and hepatitis each year after swimming, kayaking, fishing, or simply wading in water they thought was safe?
It is comprehensible that in developing countries people may not be educated to understand the consequences of dumping garbage and sewage in the waterways and the ocean. Many areas have absolutely no infrastructure in place providing treated water and ensuring that septic fields are adequate and do not leach into the water table used by the community.
In fact, the source of water may be distant from the village. It is estimated that in many sub-Saharan African societies, a woman spends 60 percent of her day hauling water. And, depending upon the distance that can be merely hauling enough water to cook with, not enough to use for cleaning and bathing as well .
But the United States passed the Clean Water Act in 1972, essentially requiring local governments to provide an infrastructure to collect wastewater and treat it before returning it to homes for reuse.
So why is sewage in every river and stream?
The treatment plants constructed with the initial federal grant money are old now. The average age of the 600,000 miles of sewer pipes across the country is 33 years old with some nearly 200 years old. Some are made of wood. Many are made of lead which corrodes.
Older sewage systems carry everything Americans flush down the toilet, which unfortunately includes pharmaceuticals and personal hygiene products, along with human waste.
The same system also carries the storm water that washes from the sidewalks, streets and gutters. Storm water frequently contains automotive chemicals, pesticides, fertilizers and trash.
Newer systems separate the two flows, but with urban sprawl causing the removal of trees whose root systems could otherwise soak up rainwater and new expanses of impervious concrete and asphalt being laid, a heavy rain causes storm water to end up in the sewer and contributes to raw sewage overflows from pipes and manholes.
Each year 860 billion gallons overflows from sewer systems across America and ends up in our waterways .
Emergency situations: The best way to get clean water
Boiling is the best way to insure clean water. Iodine tablets are next.
There are inexpensive filters on the market now which everyone should take with them while visiting developing countries and to use on long hikes. The simplest are small straw filters with membranes, iodized crystals and carbon which can be placed directly into a moving stream and sucked through for water.
Check out how these handy filters work on Amazon:
There are also filters that fit on the openings of water bottles. These can be found where camping equipment is sold.
Another option is a water bottle with an ultraviolet light, also sold with camping or sporting equipment.
You can find one example here:
In an emergency where you don’t have a filter but do have bleach, a few drops of chlorine bleach per quart will sanitize water.
If you are outdoors and can find the materials to build an apparatus that can use the sun to distill available water, that works.
Some emergency agencies have utilized bicycling to power a filtration system that pulls water from a source and runs it through a filter.
If you don’t have anything and you are dehydrated or need to wash, choose a water source that is not near any human, animal or industrial discharge, preferably a spring, but definitely choose moving water over brackish water.
Methods to clean polluted water
Aeration by spraying the water into the air to pick up more oxygen is a method to treat ground waters to remove iron, manganese and sulfur, sometimes naturally occurring, sometimes not, but a problem for those who get their water from a well or cistern .
Mud can be separated from water by a variety of ways, from filtering through cheesecloth or even natural materials such as grasses to simply allowing it to settle, but this will not remove harmful microorganisms.
Sedimentation, using gravity to let suspended particles fall to the bottom is one of the initial steps water treatment plants use to purify water after the water has passed through a screen and then through a grit chamber where small pebbles and the like settle.
After the sewage leaves the settling or sedimentation tank, it is generally pumped into an aeration tank where it is mixed with air and sludge loaded with bacteria.
The bacteria break down the organic matter into harmless by-products over a period of hours.
The partially treated sewage then flows to another sedimentation tank to allow excess bacteria to fall out and settle.
Completing this secondary treatment phase, chlorine is added to kill pathogenic bacteria and reduce the bad smell. In situations where excess water is discharged to surface waters, excess chlorine must be removed so that fish and marine life are not killed.
Conversely, ultraviolet light or ozone are used for disinfection in lieu of chlorine.
Other heavy metals and toxic pollutants for industrial discharge require advanced treatments like filtration, chemical oxidation, carbon adsorption, distillation, and reverse osmosis . These are not always used and that is why many people opt to also filter their water once in-house.
In-house systems may include an ultraviolet light purification system, an entire house water purifier, a partial system to filter water to a particular sink or even just a purifier that attaches to the spigot.
In-house systems generally remove particles larger than 5 microns from the water and are capable of removing up to 95 percent of the residual water contaminants, including chlorine, sediment, herbicides, pesticides, rust, and other chemicals.
Additionally, water filters attached to pitchers can be used to purify a pitcher of water at a time. These typically utilize a charcoal filter.
Reverse osmosis purification systems can be purchased for removing salt from water as well .
Scientists are researching how water-related diseases behave and are spread. As we learn more about pollutants, we can continue to create solutions to effectively prevent water pollution problems.
Much of the water pollution disease in developing countries could be prevented through adequate sanitation facilities, safe water supplies, and improved hygiene practices such as simply washing hands with soap and clean water. Disinfection should also be provided at the point-of-use.
For chemical pollutants, there must be sufficient corporate responsibility and accountability, and industry regulation and enforcement globally to prevent water pollution, and all efforts possible should be made to create environmentally-friendly industrial alternatives that make toxic chemicals unnecessary, or at least are significantly reduced. We must begin to pattern all of our business practices after nature and cease the production of toxic waste.
In the same spirit, we must also seek to use the safest, and the most ecologically-friendly products in our own homes and lives, and we must properly dispose of any toxic household chemicals at hazardous waste collection facilities.
We must also choose to support only those companies who support sustainability with their business practices and advocate for the legal protection of our water resources from pollution.
 http:/ https://globalhydration.com/waterborne-disease/common-waterborne-disease-bacteria-viruses-cysts//www.who.int/news-room/fact-sheets/detail/trachoma