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Human Activity, Biosphere and Ecology!
Human Activity:
Human activity leading to waste generation and pollution is shown schematically in Fig. 1.1. The waste produced may be in different state of aggregation, such as solid particles, particles suspended in a fluid, dissolved solutes, vapor and gas.
Some of the wastes, discharged into the biosphere are directly or indirectly harmful to some living species or other, or to the entire biotic community. These wastes are referred to as pollutants. The biotic community is made up of all the living beings: the tiniest members being microbes and the largest members being certain species of whales and trees. Man is the most important member of this community. He is responsible for causing pollution and he is capable of combating pollution.
Man has realized rather recently that his existence on earth is neither independent of the other living beings nor of the abiotic environment. It has also dawned on him that nature (the biosphere) cannot assimilate all the wastes generated by him. Pollution resulting from his activities, particularly from industrial activities has now reached a staggering magnitude. This not only concerns the developed countries, but it is also causing anxiety to the developing countries.
This realization has led man to study the inter-relation (dependence) between the different living beings and their surrounding environment. The environment is made up of land, water, air and the physical factors in the immediate vicinity of a biotic community. This branch of study is known as ecology.
Pollutants are those wastes, which cause adverse effects on the biotic community of an ecosystem by interfering with the growth or health or comfort of different species. In a narrow sense, Pollutants are those substances or effects, which are produced as a result of natural processes and or human activities, that are harmful to man directly or indirectly or prejudicial to his amenities and property.
ADVERTISEMENTS:
Ecology is a branch of science, which deals with the distribution, and the population of living beings and their dependence and interaction with surrounding environment. The composition of the biotic community is not uniform throughout the biosphere. The different species making up a community, and the population of each species in a locality, depend on the local abiotic environment, including the weather.
Pollutants, discharged in a locality, affect the biotic community in the neighborhood immediately after the discharge and may affect the entire biotic community in the long run. Hence, for ecological studies selected portions of the biosphere (termed as ecosystems) are considered at a time, and the effects of pollutants (which are likely to be discharged as a result of a proposed activity) on the local flora and fauna of these ecosystems are investigated. Such studies are known as “Environment Impact Assessment” (EIA). The aspects, which need’ examination, for preparation of an EIA report depend on the activity being planned.
Prior to carrying out an activity which is likely to affect an ecosystem, it is desirable to take a stock of the local environment, that is, to prepare an environmental inventory. Based on the environmental inventory, and the EIA Report, an Environmental Impact Statement (EIS) is prepared to highlight the environmental changes expected as a result of a proposed activity. It is to be presented in a specified format as laid down by the national/state/local authority that finally decides about the implementation of the activity.
An Ecosystem:
An Ecosystem in the broadest sense is the entire biosphere with all the living beings and physical factors and chemical environment, which makeup the non-living surroundings sustaining life. Since it is not possible to consider the entire biosphere in an investigation, an ecosystem implies a portion of the biosphere where some living beings are in coexistence with their immediate surrounding environment. An ecosystem is more or less a closed system from which a small amount of material may leave or into which a small amount may enter compared to the amount in internal circulation.
An EIA Report should be prepared to predict the biological and physical changes, which are likely to occur as a result of any proposed activity. It should include suggestions about a new legislation/a change in the existing policies and programmes related to (a) land use pattern, (b) industrialization and (c) operational procedures.
Expected effects on human health and well-being, as a consequence of the proposed activity, should also be mentioned in the report. The report would help in understanding the social, cultural and aesthetic changes in the surroundings, which may occur as a result of the proposed activity.
An Environmental Inventory:
An Environmental Inventory is a compilation of the abiotic environmental information in a locality, prior to implementation of a proposed activity.
