Electronic thermostats, as opposed to mercury thermostats, can be programmed for certain thermostat control therefore resulting in environmental and monetary benefits through saving fuel. Barometers, Manometers, and vacuum gauges that are found in machinery may contain mercury. Many mercury-free alternatives exist. Mercury has been known to have harmful effects on fish, birds, and mammals. Mercury enters the environment through a number of fuel combustion, incineration, and industrial processes, as well as through some natural sources.
Atmospheric concentrations are, for the most part, very low.
Mercury is deposited by way of wet and dry processes to forest ecosystems. It then accumulates in highly toxic forms in the food chain of aquatic ecosystems. This is detrimental to aquatic organisms, which in some cases leads to problems in human health. Mercury exposure from food occurs most often through consumption of mercury contaminated seafood or plants, such as rice. Continued exposure results in stumbling, slurred speech, constricted visual fields, and impaired hearing.