Some of the commonly found metals in the lake include: lead, zinc, silver, gold, copper, cadmium, mercury, arsenic, molybelenum, selinium, magnesium and silicon. These heavy metals (HM) enter the lake from rain (atmospheric deposition), stream and river inflows. Since there is no outlet, heavy metals, often in the form of inorganic soluble salts, accumulate. Heavy metals end up in streams from weathering, mining, milling, and refining of surrounding mountains. If concentrations of these heavy metals persist, they could become toxic to life forms. It is actually currently unknown how much or little the heavy metals in the GSL are impacting the ecosystem. Scientists once thought the brine layer in the lake effectively sequestered heavy metals. More recent studies on mercury and selenium concentrations show that the exact opposite could be happening—the chemistry of the lake is actually converting, or methylating, the mercury and thus making it available for absorption into algae and microorganisms. Brine shrimp feed on algae and incorporate heavy metals into their fatty acids. When the birds eat brine shrimp, they accumulate even more heavy metals in their system. This process is known as bioaccumulation and can be highly toxic for birds and other animals higher up in the food chain, including humans. For this reason, the Utah Department of Health recommends limiting the consumption of certain bird species at GSL.
Keeping all this in mind, many people and nutritionists consider heavy metals (excluding mercury) available in the lake curative! Numerous visitors recount that swimming in the lake helped ease their bones and muscles. Spas, such as Saltair, were extremely popular and world-renowned as curative and luxurious (see Industries page). Companies have been harvesting heavy metals (which they call trace minerals) for decades as nutritional supplements with known curative properties for arthritic related symptoms and calcium issues. They suggest that conventionally grown foods contain the nutrients appropriate to grow healthy plants, which we also need, but the plants tend to lack other nutrients not supplied by artificial fertilizers. These companies assert that the products they sell are safe and non-toxic.