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Periphyton can contain species of cyanobacteria that are toxic to humans and other animals. [1] In fresh water, excessive growth and subsequent death and decay of periphyton can have undesirable effects: depleting oxygen in the water, altering its pH, and clogging the space between gravel and sand (the hyporheic zone).
Toxic: a chemical that has a median lethal concentration (LC 50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats ...
The only known technique of prevention is to avoid ingesting the poisonous alkaloids. Some methods of control have been defoliation in areas in both Oregon and California. Also mass relocation efforts of moths, flea beetles and seed flies have been made in hopes that they will eat the toxic plants and help control the population of the plants.
Some animal species use bioaccumulation as a mode of defense: by consuming toxic plants or animal prey, an animal may accumulate the toxin, which then presents a deterrent to a potential predator. One example is the tobacco hornworm, which concentrates nicotine to a toxic level in its body as it consumes tobacco plants. Poisoning of small ...
Some of these toxic chemicals are discharged into lakes, rivers, the ocean, and groundwater. Animals, plants, and water surfaces can also be exposed from airborne chemical emissions caused from cities, factories, and fires (Fantke, 2020). Chemical sludge often gets into agricultural and industrial soils as well. [citation needed]
Cyanobacteria (blue-green algae) bloom on Lake Erie (United States) in 2009. These kinds of algae can cause harmful algal bloom. A harmful algal bloom (HAB), or excessive algae growth, is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, water deoxygenation, mechanical damage to other organisms, or by other means.
It is "semimetallic property, is prominently toxic and carcinogenic, and is extensively available in the form of oxides or sulfides or as a salt of iron, sodium, calcium, copper, etc." [19] It is also one of the most abundant elements on earth and its specific inorganic forms are very dangerous to living creatures (animals, plants, and humans ...
Air pollution can cause diseases, allergies, and even death; it can also cause harm to animals and crops and damage the natural environment (for example, climate change, ozone depletion or habitat degradation) or built environment (for example, acid rain). [2] Air pollution can occur naturally or be caused by human activities. [3]