TMA Testimony on SB 506 Mercury Advisory

Testimony: Senate Bill 506 by Senator Robert Deuell, MD

House Committee on Public Health   

By: A. Nelson Avery, MD
May 19, 2011

Chair Kolkhorst and members of the committee. My name is A. Nelson Avery, MD. I serve as the Director of the Preventive Medicine Residency Program at the Texas A&M Health Science Center College of Medicine and I am based in Round Rock. I am board certified in internal medicine and occupational medicine and hold subspecialty certification in medical toxicology.   

I am here today on behalf of the 45,000 members of the TMA and we are pleased to express our support for Senate Bill 506. The bill would make changes to the consumption advisories that the state must issue on mercury contamination in fish.   

Mercury is in our air, water, and soil. We all are exposed to mercury in some way, but fish and other seafood products are the main source of methyl mercury in our diets (1000 to 10,000 times higher than other sources, including meat, eggs, dairy, cereals and vegetables).  

SB 506 strengthens our state’s environmental health system by lowering the levels of mercury that would require the state to issue a consumption advisory.  Lowering the level to 0.3 mg/kg from our current level of 0.7 mg/kg will put Texas in line with the national standard.  

The US EPA used a scientific risk analysis to adopt a standard of 0.3 ppm (= 0.3 mg/kg).  This rule protects adults, children and the fetus. 

When a pregnant woman consumes fish or shellfish contaminated with mercury, the mercury can readily pass through the placenta. Mercury exposure can then affect the highly sensitive developing brain of a fetus.   

This can result in low birth weight, delayed speech, loss of vision and hearing, loss of muscle coordination (causing delayed walking, tremor, spasticity) — resembles cerebral palsy.  

Mercury has a fairly long half-life (2 months) —will take ~ 5 half-lives to eliminate a single exposure.  The brain effects of methyl mercury poisoning are cumulative and irreversible, and there is no treatment.  

Fish and shellfish have very important nutrients, including low-calorie protein and omega-3 fatty acids and we encourage a diet that includes seafood. While almost all fish contain mercury, fish from some water bodies have higher levels of mercury, and this generally includes larger fish.   

Consumption advisories are unnecessary for the top 10 seafood species: canned tuna, shrimp, pollock, salmon, cod, catfish, clams, flatfish, crabs and scallops), because these all have less than 0.2 mg/kg in their flesh.  The freshwater fish of particular concern are largemouth bass and walleye in certain areas.  That’s why the use of local advisories is so important — so that pregnant or nursing mothers can make informed choices.  

The Texas Legislature has supported efforts to ensure women have access to information that help them make good decisions to protect their health. We have more than 400,000 births each year in Texas. We must also have a rigorous public health advisory system based on current science so we can protect the health of all Texans. Many other states already have established lower advisory levels than Texas. We encourage you take steps to protect Texas’ women and young children from deadly mercury levels. 

82nd Texas Legislature Testimonies