Water Quality and Food Safety – I

Importance of Water

Water is the source essential to sustain the life on earth, since it is not only required for biological processes, where it’s abundant presence with typical physical and chemical characteristics are very important because water has a very stabilizing effect on interplanetary (sunlight, cosmic radiation and earthly (climate) processes. Nonetheless, water is the most important source of transportation on earth whereas cargos/goods that are transported through ships as primary transport source, while dissolved and suspended compounds are also transported where type and concentration of these compounds determine the water quality. Considering the total earth surface of 510 million sq.km, 73% of earth surface covers by it amounting to 1,600 million cubic kilometers. 

Thus satisfactory (adequate, safe and accessible) supply must be available to all as to the world health organization (WHO) because improving access to safe drinking-water can result in tangible benefits to health, where every effort should be made to achieve a drinking-water quality as safe as practicable. Safe drinking-water, as defined by the WHO guidelines, does not represent any significant risk to health over a lifetime of consumption, including different sensitivities that may occur between life stages. Those at greatest risk of waterborne disease are infants and young children, people who are debilitated or living under unsanitary conditions and the elderly. Safe drinking-water is suitable for all usual domestic purposes, including personal hygiene. Nonetheless, WHO guidelines are applicable to packaged water and ice intended for human consumption. However, water of higher quality may be required for some special purposes, such as renal dialysis and cleaning of contact lenses, or for certain purposes in food production and pharmaceutical use. Those who are severely immuno-compromised may need to take additional steps, such as boiling drinking water, due to their susceptibility to organisms that would not normally be of concern through drinking-water. However, WHO guidelines may not be suitable for the protection of aquatic life or for some industries.

Water Chemistry

Water is by far the most common liquid on the Earth’s surface, and its unique properties enable life to exist where water is usually regarded as a public resource or a common good, because it is essential for human life and society. However, water also is an economic resource which is sold as a commodity, and water rights in are one of the major reasons for continuous source of conflict in many civilizations. Beyond these perspectives, water holds a special place in human society.

As a recognized field of inquiry, water chemistry developed in the mid-twentieth century (late 1950s and early 1960s) at the dawn of the “environmental era”, whereas its origins as subareas of specialization in many other disciplines date back to the early twentieth century and even before. For example, the chemical composition of lakes and the oceans has been of interest to limnologists and oceanographers since the early development of those sciences in the late nineteenth century. Similarly, geochemists long have been interested in the composition of natural waters, in addition to longstanding interests in the composition of geo-solids. Water chemistry also was a significant component of the field of environmental engineering (or sanitary engineering, as it was known prior to about 1960), in part because of the important role of chemical processes in drinking water treatment. Werner Stumm (1924–1999) is widely considered to be the founding father of water chemistry. His contributions to the development of the field are both broad and deep, not only in terms of the span of his research contributions, but equally important as the mentor of many students who became leaders in the field and his authorship (with James Morgan, his first Ph.D. student) of the important textbook Aquatic Chemistry (1970).

For chemists, water is a small, simple-looking, and common molecule, H2O, but they also know it has many unusual and even unique properties, as discussed below. For civil engineers, water is a fluid to be transported via pipes and channels, and when it occurs in rivers and streams, it is viewed partly as an obstacle to transportation, for which bridges need to be designed and constructed, and partly as an energy-efficient means of transportation and shipping. Scientists in many other disciplines have their own viewpoints about water that reflect how it interacts with their science.

Water (H2O) in its purest form at room temperature is odorless, nearly colorless with a hint of blue and tasteless, which exist in nature as a polar inorganic compound. Due to its major property of being a universal solvent, it is in your body, the food you eat and the beverages you drink, which further help to clean yourself, clothes, dishes, car and everything else around you as well as you can travel on it or jump in it to cool off on hot summer days. Many of the products that you use every day contain water or were manufactured using it. At its most basic, water is a molecule with one oxygen atom and two hydrogen atoms, bonded together by shared electrons, which is a V-shaped polar molecule, and it is charged positively near the hydrogen atoms and negatively near the oxygen atom. Water molecules are naturally attracted and stick to each other because of this polarity, forming a hydrogen bond. This hydrogen bond is the reason behind many of water's special properties, such as the fact that it's denser in its liquid state than in its solid state (ice floats on water).

History of Water Treatments

The controlled use of water dates back to at least 8,000 B.C. when farmers in Egypt and parts of Asia trapped floodwaters for crop irrigation. Thus concept of using irrigation canals to bring water to crops, rather than waiting for a flood, was first developed about 2,000 B.C. in Egypt and Peru. The city of Karcho, what is now call Jordan, built two aqueducts to bring an adequate supply of water for the city's population by about 1,000 B.C. This is the first recorded instance of a planned municipal water supply.

Early water treatment was surprisingly advanced, although rarely practiced. An ancient Sanskrit manuscript, from what is now India, advises that drinking water should be kept in copper vessels, exposed to sunlight, and filtered through charcoal where ancient Egyptian inscriptions give similar advice. Many of these methods are still used today. The Greek medical practitioner Hippocrates suggested that water should be boiled and strained through a piece of cloth about 400 B.C. Despite these early references, most people drank untreated water from flowing streams or subterranean wells. As long as there were no sources of contamination nearby, this was a satisfactory solution.

As the population of Europe and other parts of the civilized world grew parallel to the industrial revolution, their sources of water became increasingly contaminated. Thus in many cities, in Europe and other parts, where  rivers that served as the primary sources of drinking water were so badly contaminated with sewage that they resembled open cesspools which act as host for Cholera, typhoid, and many other water-borne diseases. In 1800, William Cruikshank of England demonstrated that small doses of chlorine would kill germs in water and by the 1890s, several municipalities found that slowly filtering water through beds of sand could also significantly reduce the incidence of disease. The public outcry for safe drinking water reached such a crescendo that by the early 1900s where most major cities in the United States had installed some sort of water treatment system by that time.

Even through water treatment is established, water contamination remained a serious concern as an increasing amount of industrial wastes poured into the rivers and lakes. As the adverse health effects of lead, arsenic, pesticides, and other chemicals became known, the United States federal government was obliged to pass the Water Pollution Control Act of 1948. This was the first comprehensive legislation to define and regulate water quality, which was later followed by a series of increasingly tougher requirements, culminating in the current Environmental Protection Agency (EPA) water quality standards.

The Water Quality Parameters

Over the years water quality and attitudes towards it have changed greatly particularly in the food and beverage industries. The most significant criteria have been the appearance, especially in the beverage industry. However, factors such as taste have gained great importance over the years. However, probably the most important factor to arise in terms of quality due to water pollution is the quantity of coliform bacteria that is present in the water supply.

The appearance or turbidity is a measure of cloudiness and color, where accepted turbidity in most food and beverage production is 10 units. But ice has the exception with a turbidity factor of 5 units and most carbonated beverages with a turbidity factor of 2 units and water used in distilled spirits can have a turbidity factor as high as 10 units. Color is only specified for baked good at 10 units and carbonated beverages at 10 units and ice with 5 units.

Taste and odor of water is another important factor in food processing and the cleaning of the food processing machines/equipment. However there has yet to an absolute standard established for taste and odor for water in these applications. Since water is odorless, any water with a perceived odor could be considered unacceptable which is also true for taste even though water can often be described as tasting good or tasting bad. Water that tastes bad may contain dissolved mineral salts such as oxides from iron and/or organic matter such as dried leaves bacteria and algae.