Definition of Water Pollution
Water pollution is defined as any alteration in the quality, nature, or characteristics of water, making it unfit for use. This occurs when pollutants such as chemicals, bacteria, or even thermal or radioactive energy are introduced into aquatic ecosystems, including groundwater or surface water sources like lakes, streams, rivers, estuaries, and oceans. These pollutants impair the performance of ecosystems and lead to visible signs such as murky water, foul odors, or floating debris. However, some forms of water pollution are invisible and can include harmful chemical saturation that cannot be seen or smelled.
Water quality can be assessed using several standards, including:
- Chemical Standards: Measuring the concentrations of hazardous chemicals in water samples. High concentrations indicate contamination.
- Biological Standards: Examining the ability of organisms such as fish, insects, and other invertebrates to thrive in the water. The presence of diverse species generally suggests good water quality.
Sources of Water Pollution
Water pollution can originate from various sources and is categorized based on the type and nature of pollutants:
Chemical Pollutants
- Crude Oil and Petroleum Products: Floating on the water’s surface as shiny oil slicks due to their lower density compared to water, petroleum pollutants include substances like gasoline, diesel, kerosene, and lubricating oils.
- Fertilizers: Excessive runoff of fertilizers containing nitrates and phosphates leads to toxicity in aquatic organisms and humans, favoring the growth of harmful algae and bacteria.
- Chlorinated Solvents: Dense, toxic compounds such as trichloroethylene and carbon tetrachloride that sink and contaminate water.
- Pesticides and Pharmaceuticals: Include hazardous substances like DDT and antibiotics.
- Radioactive Materials: Elements like plutonium, strontium, cesium, and uranium used in industries or as byproducts from nuclear activities can significantly harm aquatic systems.
Biological Pollutants
Biological pollutants include high populations of algae, viruses, and bacteria that decompose organic waste or result from improper waste disposal methods.
Point and Nonpoint Sources
- Point Sources: Easily identifiable sources such as wastewater from factories or oil spills.
- Nonpoint Sources: Diffused sources like agricultural runoff and urban drainage systems.
Types of Water Pollution
- Surface Water Pollution: Includes contamination of rivers, lakes, and oceans, often caused by industrial discharge, agricultural runoff, or urban waste.
- Groundwater Pollution: Typically harder to detect, it results from pollutants like pesticides, heavy metals, or industrial solvents seeping through soil layers.
Effects of Water Pollution
On Humans
- Increased prevalence of waterborne diseases like cholera, typhoid, and dysentery.
- Exposure to heavy metals like mercury and arsenic causes severe health problems, including kidney failure and liver damage.
- Pregnant women face risks such as low birth weight for babies due to exposure to chemical contaminants.
On the Environment
- Acid rain harms aquatic life in lakes and rivers.
- Altered chemical composition of water disrupts aquatic ecosystems.
- Bioaccumulation of harmful chemicals in marine organisms affects the food chain, ultimately impacting humans.
Water pollution threatens not only the health and survival of aquatic ecosystems but also the availability of clean water for drinking, agriculture, and recreation.
