Gallium and gallium semiconductor compounds

Gallium is a soft, silvery metal with an atomic number of 31. Gallium compounds are used in semiconductor materials, optoelectronic devices (e.g., laser diodes, light-emitting diodes photodetectors, and solar cells), cancer and malaria chemotherapy, antimicrobial, and dental materials. The production of gallium continues to increase due to the demand for high-powered radio frequency smartphones. Analytical methods for gallium include atomic absorption/emission spectrometry, X-ray fluorescence, and, more recently, inductively coupled plasma mass spectrometry. The main health concerns for gallium have been centered on workers in the semiconductor industry engaged in the production of gallium-based devices; however, monitoring of workers is sparse. Gallium is transported in the circulation bound to transferrin. Its competition with iron for transferrin-binding might account for its being an anticancer, antimicrobial agent, antifungal agent, or antiparasitic agent. Toxicity studies in experimental animal systems have shown gallium nitrate, gallium arsenide, and gallium oxide to produce toxicity to the lungs, immune system, kidneys, and hematopoietic systems. The International Agency for Research on Cancer has classified gallium arsenide as a human carcinogen. Studies of semiconductor workers are limited, but clinical trials in humans treated with gallium nitrate for various cancers have demonstrated renal toxicity as the primary side effect.