Environmental Threats: Toxic Substances, Radiation, Habitat Loss
Other Toxic Substances
Toxic substances are chemicals whose manufacture, processing, distribution, use, and disposal pose a risk to human health and the environment. Most of these toxic substances are synthetic chemicals that enter the environment and persist there for long periods. In areas where chemicals are produced, significant concentrations of toxic substances can accumulate. If these substances seep into the soil or water, they may contaminate the water supply, air, crops, and domestic animals. Exposure has been associated with human birth defects, miscarriages, and organic diseases. Despite the known risks, the problem is not being adequately addressed. Recently, more than 4 million new synthetic chemicals were manufactured within fifteen years, and 500 to 1,000 new products are created annually.
Radiation
Although atmospheric nuclear tests have been banned by most countries, significantly reducing a major source of radioactive fallout, nuclear radiation remains an environmental problem. Nuclear plants routinely release small amounts of nuclear waste into the water and atmosphere. However, the main danger is the possibility of a major nuclear incident, which releases huge amounts of radiation into the environment, as happened in Chernobyl, Ukraine, in 1986. A more serious problem facing the nuclear industry is the storage of nuclear waste, which retains its toxicity for 700 to 1 million years. The safety of geological storage for such extended periods is problematic. Meanwhile, radioactive waste accumulates, threatening the integrity of the environment.
Loss of Wildlands
An increasing human population is encroaching upon remaining wilderness, even in areas previously considered safe from exploitation. The insatiable demand for energy has prompted the exploitation of gas and oil in Arctic regions, threatening the delicate ecological balance of tundra ecosystems and their wildlife. Rainforests and tropical forests, especially in Southeast Asia and the Amazon, are being destroyed at an alarming rate for timber and to clear land for pasture, crops, pine plantations, and human settlements. This tropical deforestation could lead to the extinction of up to 750,000 species, representing the loss of a wide variety of potential products, including food, fibers, pharmaceuticals, dyes, gums, and resins.
Soil Erosion
Soil erosion is accelerating on all continents and degrading approximately 2 billion hectares of cropland and pasture, posing a serious threat to global food supplies. In the developing world, the growing need for food and firewood has resulted in deforestation and cultivation of steep slopes, leading to severe erosion. To further complicate the problem, there’s a significant loss of prime farmland due to industrial expansion, wetlands loss, urban sprawl, and road construction. Soil erosion, along with the loss of farmland and forests, also reduces the land’s capacity for moisture conservation and adds sediment to streams, lakes, and reservoirs.