PERCHLORATE

Usage

An oxidant in solid rocket propellants, ordnance, fireworks, airbag deployment systems, and commercial fertilizers.Perchlorates are also detected in consumer products such as bleach and sealing gaskets for food containers.

Clinical implications

There are some mutations in the NIS gene (SLC5A5) that cause hypothyroidism and thyroid dyshormonogenesis. Anti-NIS antibodies have been found in thyroid autoimmune diseases. Defects of the pendrin gene (PDS, SLC26A4) result in Pendred Syndrome associated with profound sensorineural hearing loss and a thyroid condition called goiter.

Origins of environmental perchlorates

Natural and anthropogenic sources. Five perchlorates are manufactured in large amounts as magnesium, potassium, ammonium, sodium, and lithium salts.

Exposure routes

From food (especially leafy green vegetable and milk) or drinking water, but not through the skin. For fetuses and infants, from the placenta, breast milk (or cow milk), infant formula, and baby food. The level in urine for children of 0.5–6 years of age is 2–3 times higher than for children 10 or older.

Description

Perchlorate has been known to inhibit the transport of iodide into the thyroid gland, and it has been clinically used for the treatment of thyrotoxicosis since the 1950s. Industrially, perchlorate has been produced in large amounts for rocket fuels and military applications.It was discovered in the 1990s that perchlorate remains unreacted in environments such as soil, plants, and animals located in or near many military installations and rocket manufacturing facilities, at potentially thyroiddisrupting levels.

Physical properties

Colorless, no odor, and stable at room or normal temperature. Perchlorates are soluble in water (249 g/L for ammonium perchlorate), and do not volatilize from soil or water surfaces.