Exposure to diatomaceous earth can have both positive side effects, such as removing parasites, and negative side effects, such as eye or lung irritation. The side effects of diatomaceous earth vary depending on the specific conditions of the exposure.
Diatomaceous earth is a dust-like substance typically used in the home and garden to remove spiders and similar pests. If the dust becomes airborne, it may enter a person's mucous membranes and cause eye irritation, or the powder may be inhaled and cause coughing and other lung irritation. Amorphous and crystalline diatomaceous earth may cause short-term or long-term side effects when the dust enters the eyes or is inhaled through the nose or mouth.
Food-grade diatomaceous earth is thought to have some health benefits when consumed in small quantities, according to Processed-Free America. For example, some of the positive side effects can include removing parasites, lowering cholesterol levels and improving digestion. The active ingredient in diatomaceous earth is silica, a nutrient that human bodies require.
Crystalline diatomaceous earth is not safe for human consumption and may have harmful side effects, such as bronchial irritation that occurs when crystalline diatomaceous earth is inhaled. Amorphous, food-grade diatomaceous earth is safe for most applications and is not typically associated with long-term, negative side effects. Crystalline diatomaceous earth, however, has been shown to increase the risk of some cancers with repeated, long-term exposure, according to the National Pesticide Information Center.