Iodine in biology air should not exceed 1 mg/m³ (eight-hour time-weighted average). When mixed with ammonia and water, elemental iodine forms nitrogen triiodide, which is extremely shock-sensitive and can explode unexpectedly. Excessive iodine intake presents symptoms similar to those of iodine deficiency. Commonly encountered symptoms are abnormal growth of the thyroid gland and disorders in functioning, as well as in growth of the organism as a whole. Iodide toxicity is similar to (but not the same as) toxicity to ions of the other halogens, such as bromides or fluorides. Excess bromine and fluorine can prevent successful iodine uptake, storage and use in organisms,
Suprapedal gland the suprapedal gland of the land snail "Pomatias elegans" there are three types of gland cells: cells producing mucoproteins, cells producing proteins and cells producing sulphated mucopolysaccharides. For example, the land slug "Leidyula floridana" has gland cells in the suprapedal gland which produce weakly acidic mucopolysaccharides, neutral mucopolysaccharides and a protein. Suprapedal gland The suprapedal gland or mucous pedal gland is an anatomical feature found in some snails and slugs. It is a gland located inside the front end of the foot of gastropods. The term "suprapedal" means "above the foot". The function of this gland is to produce mucus.