Mercury's Rising Impact

Environmental Protection

Mercury is getting a lot of attention, both in the popular press and in state and federal regulatory agencies. Combustion systems, like coal-fired power plants, industrial boilers, incinerators, and cement kilns, are sources of mercury emissions to the air. This article outlines the mercury emission regulations that apply to different combustion systems and the best demonstrated means to control these emissions from combustion sources. This article focuses on utility and industrial combustion systems because they are the highest emitters and face the greatest reductions and tightest scrutiny.

The primary exposure route to mercury for humans through eating fish. Mercury concentrations in the air are very low and don't represent a direct health threat, but mercury in the air deposits on land and water, finding its way to lakes and rivers, where bacterial action transforms it into a highly toxic form (methyl mercury), which builds up in fish. The annual global mercury emissions from all sources, natural and anthropogenic (human-caused), total roughly 6,600 to 7,200 short tons (non-metric tons) per year. The United States contributes an estimated 5 percent of the global human-caused mercury emissions (or about 167 short tons). Figure 1 shows the contributions from various industrial sectors in the United States to air emissions of mercury.

The U.S. Environmental Protection Agency (EPA) currently limits emissions of mercury from certain categories of combustion sources on an annual basis, as outlined in Table 1. EPA uses a Maximum Achievable Control Technology (MACT) standard under the Clean Air Act to specify control technologies for mercury emissions from most combustion sources, with the exception of coal-fired power plants. For incinerators and municipal waste combustors, the MACT standard is based on input feed rates to the combustor. The MACT standard for coal-fired industrial boilers specifies mercury emissions verification either by control of mercury in the fuel or by periodic stack testing.

Preventing Mercury Release from Facility Lighting

BE EP trimmed

While the energy-saving fluorescent lighting in use at many facilities can lessen impact on the environment and the facility budget, when fluorescent bulbs burn out they need to be recycled to prevent release of their hazardous mercury content.

The Bulb Eater® lamp crusher makes it fast and cost-effective for large facilities, while EasyPak™ mail-in containers are a simple recycling method for small facilities. Learn more » Air Cycle recycling solutions