Many fish commonly caught or consumed in the Houston area are contaminated by mercury from air pollution.

Mercury is a neurotoxin and, according to the Texas Medical Association, “threatens human health and child
development.” In adults, mercury can permanently damage the brain and cardiovascular system and reduce fertility. Affected infants and young children may experience irreversible damage to their intelligence,learning capabilities, vision, and hearing.

One-fifth of women of childbearing age have mercurylevels in their hair that exceed federal health standards,
according to University of North Carolina scientists, and the US Environmental Protection Agency (EPA) warns that mercury exposure places 630,000 infants born each year at risk of irreversible harm. Also at risk are young children and those adults who eat fish daily.

Diet choices affect your mercury exposure 

Certain fish species tend to accumulate higher amounts of mercury than others. The variation is partially explained by the amount of mercury released by nearby sources of pollution. Other factors include the lifespan and diet of the fish.

In 2003, 44 states had active mercury consumption advisories covering one-fifth of all river miles, one-third of all lake acres, and two-thirds of coastal waters in the contiguous 48 states. There are some general rules of thumb that can help explain which fish are likely to expose consumers to more or less mercury.

• Large saltwater predator fish generally have high levels of mercury.
• Predator fish caught in Texas lakes may also have unsafe levels of mercury.
• Fish from Galveston Bay are generally considered safe.
• Farmed fish also appear to be safe.

These simple rules are not enough to go by - predicting or measuring mercury contamination in fish is complex, and consumers cannot be expected to deduce the level of mercury in fish available to them

Mercury gets into fish as a result of air pollution 

Mercury in the air falls to the earth as particles or in rain,and ultimately finds its way to lakes and river sediment. Bacteria and plants absorb the mercury, which accumulates up the food chain. Ultimately, mercury builds to dangerous levels in predators, such as fish, waterfowl, and people.

Coal-fired power plants are the largest unregulated source of mercury emissions. According to the EPA, 10 tons of mercury was emitted from Texas power plants in 2002. In 2002, the Parish power plant in Fort Bend County was listed as the sixth-largest source of mercury emissions in the nation.

Power plants are just beginning to be regulated for mercury pollution under federal clean air standards. In 2002, EPA scientists said current technologies could achieve a 90 percent reduction in mercury produced by power plants, but the coal and electric industries are pressing hard to avoid implementing these technologies.

Mercury is not a by-product of combustion. Rather, very small amounts of mercury are present in coal and arevented through the exhaust system when the coal is burned. Different types of coal have various levels of mercury and produce different chemical forms of it when the coal is burned.

Get involved

Several of our partners are active on this issue. GHASP supports their efforts from time to time, but does not take a leadership role on this issue since it is a statewide and national issue.

• Environment Texas - organizing state residents to press the EPA for strong regulation of mercury
• Sustainable Energy and Economic Development Coalition - challenging the State of Texas to protect public health by routinely monitoring fish for mercury contamination
  
• Save the Clean Air Act and Clear the Air - mobilizing people nationwide to press for pollution controls on coal-buring power plants