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| Define the term water pollution? What indicators are used to measure the quality of water. |
Water pollution refers
to the contamination of water bodies such as rivers, lakes, oceans,
groundwater, and even drinking water sources, by harmful substances or
pollutants. These pollutants can originate from various sources, including
industrial, agricultural, and domestic activities. Water pollution has adverse
effects on aquatic ecosystems, human health, and overall environmental balance.
Indicators used
to measure the quality of water are parameters or characteristics that provide
insight into the health and suitability of water for various purposes. Here are
some common indicators used to measure water quality:
1. Physical
Indicators:
· Temperature: High
or low temperatures can affect aquatic life and the solubility of gases in
water.
· Turbidity: Measures
the cloudiness or haziness of water due to suspended particles, which can
impact light penetration and aquatic life.
2. Chemical
Indicators:
· pH: Indicates the acidity or
alkalinity of water. Extreme pH levels can harm aquatic organisms.
· Dissolved Oxygen (DO):
Essential for aquatic life, DO levels indicate the amount of oxygen dissolved
in water.
· Nutrients:
Including nitrogen and phosphorus. Excessive nutrient levels can lead to
eutrophication and algal blooms.
· Chemical Oxygen Demand (COD) and Biochemical
Oxygen Demand (BOD): Indicate organic pollution levels by measuring
the amount of oxygen required to break down organic matter.
· Heavy Metals: Such
as lead, mercury, and cadmium. These can be toxic to aquatic life and humans.
3. Biological
Indicators:
· Biotic Index:
Measures the diversity and abundance of indicator species in an aquatic
ecosystem. Sensitive species are more affected by pollution.
· Macroinvertebrate Assessment: The
presence and diversity of macroinvertebrates can indicate water quality, as some
are sensitive to pollution.
· Fecal Coliform Bacteria:
Presence of these bacteria indicates contamination by fecal matter, which could
include harmful pathogens.
4. Microbiological
Indicators:
· E. coli: Used as an indicator
of fecal contamination and potential presence of pathogens in water.
5. Radiological
Indicators:
· Radioactive Elements:
Presence of radioactive substances in water can have health implications.
6. Toxicological
Indicators:
· Toxic Substances: Detection
of specific pollutants, such as pesticides, industrial chemicals, or
pharmaceuticals, that can be harmful to aquatic life and humans.
Monitoring these indicators
allows scientists and authorities to assess the quality of water, identify
pollution sources, and implement appropriate management strategies to ensure
safe and sustainable water resources. The choice of indicators depends on the
specific water body, its intended use, and the potential sources of pollution.