Pollution tolerance limit

Tonogai, Y., Ogawa, S., Ito, Y., and Twaida, M. Actual survey on TL (median tolerance limit) values of environmental pollutants, especially on amines, aromatic nitrogen compounds and artificial dyes, J. Toxicol. Sci., 7 193-203, 1982. 

In India, domestic and industrial wastewaters are required to meet the standards set out in the Environment (Protection) Third Amendment Rules (1993) and Water (Prevention and Control of Pollution) Act (1974). The tolerance limits for the disposal of industrial effluents into inland surface water are given in Table 23 [69]. 

Water-quality deterioration can be attributed to water pollution or contamination. Water pollution is generally defined as any physical, chemical, or biological alteration in water quality that has a negative impact on living organisms. In the stricter sense, pollution can be defined as the transfer of any substance to the environment. However, there is a tolerance limit for each pollutant, since zero-level pollution is economically and technically unpractical. The most important kinds of water quality deterioration are the following. 

The ultimate goal of the science of safety is to hold to an absolute minimum any damaging effects from handling modern technology, or, at least, to keep them within tolerable limits. In the above context, damaging effects may mean accidents caused by technology as well as other destruction or loss, e.g., through environmental pollution caused by a technical installation. 

The high visibility of water-soluble dyes released to the environment ensures that only extremely low concentrations in watercourses would not be noticed. A typical visibility limit in a river would be about 0.1 to 1 mg/1, but this varies with the colour, illumination and degree of clarity of the water. The human eye can detect a reactive dye concentration as low as 0.005 mg/1 in pure water, particularly in the red to violet hue sector [88]. There is considerable debate, however, about what level of environmental hazard is represented per se by colour in effluent. The view has been expressed that dyestuffs should not be regarded as water pollutants because at concentrations of the same order of magnitude as these visibility limits their harmful effects are negligible [89]. Nevertheless, even though this colour problem is mainly if not entirely an aesthetic one, the fact is that the general public will not tolerate coloured amenity water and the problem therefore has to be addressed and rectified [90,91,92],... 

This insanity keeps our energy costs high, economically burdens every citizen and every nation, impoverishes many undeveloped and developing nations along with their peoples, and pollutes the planet to the limit of its tolerance and beyond. On our present course, we are embarked on destroying our biosphere and ourselves along with it. 

Geochemistry can in many cases be applied to determine limits of tolerance and give warnings of dangerous increases or trace element deficiencies in water and plants. The laboratories are equipped with sophisticated instruments, which can detect all sorts of pollution, even in the atmosphere (Steinberg, 1971). 

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