In 2005, WHO published a fact sheet dealing with magnetic and electric fields' possible effect on the environment, animals, marine animals, insects, etc. Based on what we know from research today, it must be concluded that no harmful effects from fields weaker than the exposure limits for humans recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) have been demonstrated. In the fact sheet, WHO summarises research results.

About animals
Most animal studies were conducted to find out whether the fields had an effect on humans. For the majority of the tests the researchers used mice or rats, but other animals were also used, for example fruit flies, whose lifetime is fairly short, allowing researchers to quickly find out whether a specific effect has caused changes in the hereditary material. Though only a few studies focus direct on animals, researchers have looked into whether the fields could have an effect on:

• birds, mammals and reptiles navigating by the Earth's magnetic field
• domestic animals (pigs, sheep and cattle) grazing underneath high-voltage power lines
• birds and insects passing through fields close to, for example, high-voltage power lines

WHO assesses that there is not much to suggest that fields weaker than the exposure limits recommended by the ICNIRP could affect animals. In particular, researchers have not found evidence of harmful effects on cattle grazing underneath power lines. It is known, however, that the flying of various insects could be disturbed by electric fields stronger than approx. 1 kV/m (kilovolts per metre), but pronounced effects have only been demonstrated on bees in beehives made from or containing parts made from electrically conductive materials (eg metals).

Non-insulated objects with insufficient earthing that are placed in an electric field could become electrically charged and damage or disturb the animals. In Denmark, this phenomenon has been witnessed in particular when wire cages or old metal bathtubs are used as water troughs and placed beneath high-voltage power lines without being properly earthed.

Some fish navigate by the electric fields that occur when sea currents move in the Earth's magnetic field. Other fish uses the Earth's magnetic field to navigate. None of the studies conducted has demonstrated significant effects.

About plant life
No damage to wild plants or crops has been demonstrated, except to trees growing so close to, for example, power lines that they are directly scorched by the electric charges occurring very close to the power lines.