Environmental Health: Water Pollution and Quality

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There would be no life without water, and James Lovelock’s Gaia theories have suggested that there would no longer be water on Earth without life. Water and life are inextricably linked and interdependent. Water is continually being purified and recycled by natural ecological processes, and life is endlessly sustained and regenerated by water. It provides the basic living environment for the majority of life in the form of rivers, lakes, and oceans. It is the carrier of nutrients to the plants on which all animals depend and , not least, it is the greatest constituent of our bodies. All human settlements depend on a supply of water, such that it has often been the main determinant of where villages, towns, and cities have been situated.



There is now a growing water crisis which increasingly affects us all. First of all there is the increasing contamination of groundwater, rivers, lakes, and oceans; secondly, there is the overuse of water domestically, industrially, and agriculturally, which is leading to altered patterns of flow and the lowering of water tables. The two problems are closely linked. In our own homes we can look at:

• Incoming water quality

• Pollution of outgoing water

• Conservation of supplies

Although it is only water quality that has a direct effect on our health, the pollution of outgoing drainage and sewage and the overuse of water are both having an adverse effect on water quality in general. This section looks at measures we can take in our homes to help improve the quality of the water we use and the wastewater we generate.

WATER QUALITY

The quality of the water that enters our homes depends on many factors. There are the natural constituents that have always been a part of natural water sources: the dissolved gases of oxygen and carbon dioxide and the beneficial salts that give water its taste and liveliness. Then there are the additives such as chlorine and aluminum nitrate that are designed to kill bacteria and settle contaminants. After this comes the increasing list of pollutants that are contaminating the sources of our main water supplies, whether from groundwater, rivers, lakes, or reservoirs. Our main concerns here are those constituents that are or may be harmful. What follows are brief descriptions of some of the more serious offenders.

Nitrates (Fertilizer)

Nitrate fertilizer is one of the most worrisome of recent contaminants. Only half the nitrate fertilizer used in agriculture is taken up by crops; the rest is washed into streams and rivers or seeps into groundwater. Since most of our water is drawn from these sources, there is an almost unavoidable contamination: more than one-third of British water supplies contain levels of nitrate higher than European Community standards allow. This situation is particularly serious in southeast England. The effect of nitrates on our health is indirect, since it is inside our body’s that nitrates undergo chemical changes to become nitrites and then nitrous acid, which combines with hemoglobin in the blood and reduces our bodies’ access to oxygen. This causes fatigue, and in babies it can lead to “blue baby syndrome?’ People with low blood pressure or who are anemic are particularly susceptible.

Pesticides

Like nitrates, large quantities of pesticides are used in agriculture to kill insects and weeds. A considerable proportion of these chemicals runs off into rivers and groundwater, from which water supplies are taken. These chemicals are designed to be toxic in minute quantities and often work by attacking the nervous system. It is still not clear whether or not there is any acceptably safe limit for the ingestion of these chemicals.

Lead (Plumbing)

Lead is now accepted as a seriously toxic substance; we should reduce our ingestion of it to a minimum. It is one of the toxins that can originate in our housing through the use of lead pipes or the solder that links copper pipes. If your water is soft and acidic, it is advisable to replace all lead and soldered pipework that supplies drinking water taps. You can obtain advice from your local water company on both the acidity of your water and lead pipe replacement.

Aluminum

Acid rain causes otherwise inert aluminum compounds in rocks and soils to be leached out and into our water supplies. Aluminum sulfate is also added to our water supplies to settle out solid impurities.

Aluminum has recently been implicated as a possible factor in the development of Alzheimer’s disease. Although water companies are managing to reduce levels of aluminum to reasonable concentrations in our drinking water, its effect on our body is cumulative, and we should do what we can to cut down the total amount we ingest. Limiting our use of aluminum cooking utensils is perhaps the most important way of achieving this.

Solvents

There are a growing number of solvents entering the water supply (see list); it is not yet clear how seriously they affect our health, nor how effective various treatment processes are. Watch for the results of research if you are aware of this being a problem in your area.

Microbial Contamination

This type of contamination of water mains by microbes such as bacteria or viruses is rare, due to the oxidation techniques and chlorination employed by water companies.

Chemicals Added during the Treatment of Water

Chlorine, which gives modern tap water its distinctive taste, is used by water companies to kill bacteria. However, chlorine also combines with natural acids in water from peaty soil and decomposing vegetable matter to form tri-halo-methanes (THMs), of which chloroform, a toxic compound, is one. Chloroform can be released into the air in a hot shower spray. The amount of THMs in water supplies varies considerably, and water companies are working to solve this particular problem.

Fluoride

Fluoride is added to our water supplies by some water authorities because of the effect it has on hardening the enamel on teeth and thereby reducing tooth decay. However, fluoride is also toxic, and the decision to add it to water supplies remains a controversial and even emotional topic. Some scientists have linked the use of fluoride to cancer and genetic damage, and the balance of opinion internationally seems to be moving against its use in public water supplies.

Water Analysis

Proper and accurate water analysis is a difficult and exacting task and it is thus very expensive to have samples of your own tap water analyzed. However, your local water company should be able to provide you with a breakdown of at least the main constituents in your water as it leaves their plant.

DRINKING WATER

Our bodies require 1 to 2 quarts of water a day depending on activity, climate and humidity, and other factors. Add to this the water used for cooking and washing vegetables and fruit and we arrive at an average figure of around 5 quarts per person per day that is related to eating and drinking. It is obvious that this water should be of the highest quality of any that we use, but, unfortunately, a standard of quality suitable for drinking can't be guaranteed by most water companies. There are three possible responses to this situation:

• To lobby for improvements in the quality of drinking water delivered from your local water company

• To use bottled water

• To use a domestic filtering system

The first solution requires some understanding of how improvements can be made to public supplies and lies beyond the scope of this guide. We can also reduce the amount of pollution that we add to the wastewater system (for example, by not pouring paint and cleaning solvents down the sink). Also, by purchasing organic produce, even at greater cost, we can help to reduce the total amount of pesticides and synthetic fertilizers used in agriculture.

The second solution, to use bottled water, has huge ecological disadvantages, as its supply involves huge transport costs and , in some cases, the use of non-recyclable bottles. There are no standards for bottled water, so there is no guarantee that it will not contain contaminants. Also, plastic bottles themselves often contaminate the “spring water” they contain.

Water Filters

As things stand, there is little alternative but to use a filtering system for our domestic drinking water, if we want to improve its quality. The simplest method is to use a filter jug, which you can buy in almost any hardware or home-supply store. It is important to choose one that is recommended for the particular pollutants that are likely to be present in your supply. However, if you want greater ease of use, you need to install a plumbed-in system. There are three basic types:

1. Activated Carbon

This is the least expensive and most common of the three types of filter. It simply passes the water through carbon granules or a compacted synthesized cylinder of compressed carbon powder. This type of filter removes chlorine, pesticides, and organic chemicals, but not nitrates. Some (but not all) heavy metals are removed. The filter requires changing relatively frequently before it becomes clogged with pollutants. If this is not done, bacteria can be attracted to it and pollutants can be released back into the water. Alternative filters that include granules which remove nitrates are becoming increasingly common.

Carbon-based water filter

2. Reverse Osmosis

This filter consists of a semi-permeable membrane made of cellulose, through which the water is forced under pressure. This filters out most pollutants with large molecules, letting only smaller molecules through. Although it filters out all particles, bacteria, aluminum, heavy metals, minerals, salt, and nitrates, it does let many volatile organics through. It also has the disadvantage that it filters out the desirable minerals calcium and magnesium.

3. Distillation

This system is sold as one that parallels the water cycle in nature. However, it is extremely energy-consuming to run, as all the water needs to be turned to steam before being condensed. Unless the heat can be effectively used elsewhere, or solar power can be used, from an ecological point of view it should be ruled out. Distilled water is decidedly flat to the taste; also, some volatile organic chemicals condense with the water.

The judgment to be made about which system to choose will almost certainly depend on what kinds of systems are available to you. The detailed specifications of any system will need to be matched with the particular pollutants in your local water supply. Most of the systems available in Britain are the activated carbon type. Since there is no universally accepted standard for filters, ask for laboratory test reports or check consumer magazines to make comparisons.

WATER QUALITY and PERSONAL HYGIENE

Swallowing water is not the only health risk when it comes to the quality of our home water supply. Some research has actually found less chemical absorption from drinking contaminated water than from using it to wash or take a shower. In these uses, chemicals can be absorbed in two ways: through the skin and via the lungs.

• Through the skin: chemicals can be absorbed while in the swimming pool, taking a hot bath, washing up, or washing clothes by hand.

• Via the lungs: researchers, experimenting with showers and common water pollutants, found that certain toxic chemicals evaporated into the surrounding air. Increasing concentrations of the chemicals also gradually built up in the shower and spread through the home. The amount of the chemical that vaporizes increases with more powerful and hotter showers.

Some researchers believe that 50% to 60% of soluble contaminants that we absorb enter the body through the skin or lungs in the ways described. Should we then filter the water we use for baths and showers? The answer will depend on how serious the volatile pollutants are in your area as well as how often, how long, or how hot you take your baths or showers.

REDUCING OUR OWN WATER POLLUTION

The water that enters the house relatively clean leaves it in various states of contamination from organic wastes such as urine, feces, paper and food waste, as well as from all the chemicals we use: washing powder, bleach, liquid soaps, dishwasher powder, toilet cleaners and fresheners, paint solvents and cleaning liquids, etc.

The main consideration is the biodegradability of particular chemicals. There are now “green” products available of most types of washing powders or cleaning liquids, and there are also green consumer magazines which help to determine the differences between them. In many cases we can reduce our usage or dispense with these chemical products altogether.

Composting Toilets

Another way of increasing your own self-sufficiency and reducing outgoing wastewater, especially if you are not attached to a municipal sewer system, is to use a composting toilet. These are gradually gaining favor in many parts of the Western world, particularly in the United States and Scandinavia. There are a variety of different systems and they all have one thing in common: no water is used.


Composting toilet

+ The Clivus Multrum ( Sweden) model depends on having space directly below the toilet and , ideally, the kitchen so that both feces and organic kitchen waste drop into a composting chamber. A small fan and associated ducts promote air flow to ensure odorless, aerobic decomposition.

+ The Sun-Mar System (US) manages to reduce the space required by the Multrum so that it is possible to have the whole system in one unit. A small step allows you to sit on the composting unit itself. A “Bio-Drum” ensures effective aeration and sterilization and speeds up the process by rotation. This drum is activated by turning a small handle. The great advantage of this system is that it can be put almost anywhere and requires only a vent pipe.

+ The Lectrolav (UK) avoids composting within the unit by dehydrating both solids and liquids electronically to a fraction of their original volume. These dehydrated solids are then removed for composting elsewhere.

We can also treat our own wastewater organically with plants if we have the necessary external space and are independent of a local sewage system (see PLANTS section).

WATER CONSERVATION

Apart from reducing our wastewater contamination, we can also reduce the amount of water we use. While the overall amount of water used by industry is decreasing, the amount used by households and agriculture is increasing steadily. On average, each person uses in all about 135 liters (30 gallons) of water a day. Below is a table giving approximate average percentages of water used in different activities:

Activity

% of Water Used

Flushing Toilet

Personal Hygiene

Laundry

Washing Up

Drinking and Cooking

Watering Garden

Washing Car

Losses

Total

30

25

12

8

5

5

2

13

100

 

Baths, Showers, and Hand-Washing

If we have a choice between using a bath or a shower, a short shower will generally save a lot more water. Saving hot water will save energy as well. A standard shower can deliver as much as 3 gallons of water per minute. If you use a water-saving shower head instead, water consumption can be cut in half. The same approach can be applied to washing hands: various types of aerators and sprayers are available and easily attached to most sink fittings. In addition, the less water that is used for washing, the less our absorption of chemicals.

There are, of course, other ways we can vary our washing habits and save water, energy, and chemical absorption:

• Swim in a sea, lake, river, stream, or pool

• Take a cold shower

• Wash with a bowl of water and a jug.

There are countless water-saving methods that people have used to wash themselves around the world and down through the ages. Western society has sometimes become obsessed with body cleanliness beyond reason. This obsession could more profitably be turned to the cleaning up of our polluted environment.

Washing Machines

Most washing machines use somewhere between 15 and 30 gallons of water per load. This represents about twice the amount you would use if you washed your clothes by hand. There is plenty of scope for reducing the amount of water that washing machines use and for improving the energy- saving and water-saving programs. There are big differences in water consumption for different models of washing machine, and this should be a major consideration when buying a new one. One model listed in a recent consumer magazine test used an appalling 39 gallons of water on a single hot cotton wash load.

Dishwashers and Washing Up

The same rule applies to dishwashers as for washing machines. Most dish washers are very wasteful and use far more water than necessary. Compared to washing machines, however, there is even greater potential to be efficient with both energy and water, if a dishwasher has been carefully designed.

Toilets

The toilet is the most wasteful of all modern household conveniences in terms of water: this “convenience” takes about 4 to 5 gallons of tap water, mixes it with excreta and paper and flushes it into the sewer. For some houses, a composting toilet is a possible alternative, but for most people it will not be a high priority to replace an existing plumbing system. We can, however, conserve water by either reducing the amount of water flushed to a minimum, or replacing the toilet itself with one that has a low-flush design. We may also feel we needn’t flush every time. Another step to take if water conservation is a main concern is to use “gray-water” from showers, baths, or washing to flush our toilets (see WASTEWATER RECYCLING, below); an ingenious design combining a sink and a toilet (see illustration) allows us at least to wash our hands in the water before it is used for flushing.


Basin-topped cistern

Wastewater Recycling

There are three different categories of water that are drained from our houses: Rainwater, sewage, and gray water from washing clothes, dishes, and bodies. There are many arrangements for recycling gray water and /or rain water. They all have these features in common:

• Wastewater pipework collecting gray water from baths, showers, basins, washing machines, and any other source of gray water.

• A simple filter to remove any larger solid particles.

• A storage tank to store the wastewater.

• A distribution system to take gray water to where it is needed such as toilets or an outdoor tap for watering the garden or washing the car. Either a pump or a gravity-feed system can be used for this distribution system. A drip irrigation system can also be incorporated for watering the garden.

Rainwater can either be included as an integral part of this system or treated separately.

The practicality of using such a system in your house is very much dependent on your existing arrangements. There will also be differences in terms of the need for such systems in different parts of the country. For those persons who have experienced restrictions on water usage and have big gardens, there are very obvious advantages. The illustration shows gray water from upper stories used to feed toilets on the ground floor.


Rainwater collection and gray water recycling

PRIORITIES FOR ACTION

+ Obtain a water analysis from your local water company and determine what measures you may need to take, either in filtering or lead pipe removal.

+ Consider fitting a plumbed-in filter system (depending on the quality of your water). Match the system to the pollutants you wish to filter out.

+ Reduce chemical pollution carried from your home in wastewater by using biodegradable household products.

+ Reduce the amount of water used in showers, baths and hand-washing (see WATER CONSERVATION).

+ If buying a washing machine or dishwasher, choose one with a low water-consumption rating.

+ Consider exchanging your toilet and /or cistern for a more efficient design.

+ Consider installing a system for storing gray water and /or rainwater so that it can be used for flushing toilets, watering the garden, or washing your car.

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