All plants and animals use energy from sunlight. Ultraviolet exposure, or UV radiation, is electromagnetic light radiation with wavelengths shorter than visible light, so humans cannot register it in the colour spectrum. All plants and animals, including humans, are exposed to the dangers of solar UV radiation; it can cause significant damage to plants, as seen in crop yield reduction and leaf burn, and can damage animal skin health.
According to the United Nations Environmental Program Grid-Arendal, UV radiation may affect certain animal species, but it also affects insects. Plant and animal DNA absorbs UVB light, or medium-intensity waves, and that absorbed energy breaks bonds in the DNA strands. While the majority of genetic damage is repaired by cell proteins, DNA that does not mend can lead to skin cancers and other health problems, including weakened eyesight.
According to artificial UV light exposure studies on crops, UV rays decrease the crop yield in key crops, such as rice, soy, oats, beans and sorghum. The plants minimise their exposure to UV by limiting the surface area of foliage, which in turn impairs growth. The observed drop in yield, however, does not seem serious enough for scientists to sound the alarm.
Excessive exposure to UV radiation can cause cancers in mammals, including humans, and damage their eyesight. While fur protects most animals from direct overexposure to damaging rays, the radiation may damage the unprotected body parts, such as the nose, paws and muzzle.
According to a NASA education web page updated in 2001, increased amounts of UVB waves adversely affects marine plankton that populate the first 7 feet (2 meters) of ocean water. The natural response of the most chlorophyll-packed cells is to produce more light-absorbing pigments or sink lower in the water for self-protection. However, evading the sun reduces their ability to go through photosynthesis, which means they cannot grow or reproduce as normal.
UV exposure may also adversely change a species' ability to compete with other species. In the future, UV-resistant plants may prevail over UV-vulnerable ones, meaning that UV-resistant plants, such as tetraploid plants, will overtake plants easily damaged by UV rays, such as the wild, diploid version of the plant, according to research at Tokai University Japan.
- U.N. Environment Programme; GRID-Arendal: Publications: The Consequences and Effects 2: UV Radiation and Ecosystems
- Quantum Beam Science Research; 4-7 Plants Become More Tolerant to UV Light
- U.N. Environment Programme: GRID-Arendal; Crop Chart
- NASA; Education; Ultraviolet Radiation
- NASA; Earth Observatory; Ultraviolet Radiation: How it Affects Life on Earth