Federal courts have a system to keep junk science out of courtrooms. It's time Congress adopts one, too. The Senate Environment and Public Works Committee held a hearing April 17 on the Environmental Protection Agency's (EPA) recent Mercury Air Toxics Standard (MATS), which is intended to reduce mercury emissions from coal-fired electric power plants at a cost of about $10 billion per year.
The committee heard from several witnesses, some in support and some against the rule. But the testimony from one of the pro-MATS witnesses was disturbingly misleading.
Syracuse University professor Charles Driscoll was invited to testify by committee Democrats in order to bolster the notion that mercury emissions from U.S. power plant stacks are the major contributor of mercury to the Great Lakes region and that MATS would significantly improve this purported problem.
Mr. Driscoll obliged by testifying, "in many regions of the U.S., the fresh waters and coastal waters that provide food, recreation and employment to millions of people have been contaminated by mercury inputs. The major source of this mercury contamination is atmospheric deposition."
But a 2012 study in the journal Environmental Pollution noted that mercury in Lake Michigan, for example, has declined dramatically (more than 50 percent) since the mid-20th century. The study's explanation for this decline has nothing to do with atmospheric deposition of mercury, but rather it was due to the curtailment of direct industrial and wastewater discharges in the lake.
The study further noted that more research is needed to understand the wide variation in mercury among the Great Lakes, even though the different lakes each received a similar amount of mercury from the atmosphere.
These facts constitute more than just he-said-she-said as one of the co-authors of the Environmental Pollution study was none other than Charles Driscoll, who was careful not to let these inconvenient details from his own paper spoil his congressional testimony.
Regarding mercury in fish, Mr. Driscoll went on to state, "Indeed, every state in the U.S. has some sort of fish consumption advisory, and many states have blanket advisories."
Moving past the scary rhetoric, the EPA qualifies Mr. Driscoll's observations as follows: "Beginning in the early 1980s, states have monitored fish in more and more of their waters. ... As a result, increases in advisories result primarily from increased sampling of previously untested waters by states and [Indian] tribes and are not necessarily due to increased levels or frequency of contamination."
In concluding, Mr. Driscoll said, "The good news is that the science emerging from large-scale data synthesis efforts in the U.S. underscores the point that controlling U.S. sources of mercury emissions will decrease mercury contamination in the environment locally and regionally."
But the reality, as demonstrated in data from around the world, including paleo-environmental data, show that today's mercury deposition levels are neither exceptional nor alarming.
Of the estimated 12,000-plus tons of mercury emitted into the air annually (mostly from volcanic activity, forest fires and effusions from ocean and soils), only about 45 tons (less than 0.5 percent) comes from U.S. power plants - and is largely undetectable when compared to the naturally occurring background levels in our land and oceans.
This reality is already crystal-clear to the EPA, which has admitted that alleged "hazards to public health" from mercury emissions by U.S. power plants are "anticipated to remain after imposition" of its new regulations. That is, even if coal-fired power plants stopped emitting mercury entirely, environmental levels of mercury would remain the same.
So while Congress is the appropriate forum for discussion of these inconvenient details, for his part, Mr. Driscoll only contributed half-truths and partial data to the discussion.
We can hardly expect politicians to be familiar and conversant with such scientific detail and cannot expect them to be able to adequately cross-examine the likes of Mr. Driscoll (particularly within the five minutes allotted to members for questioning witnesses). There is also no opportunity in the congressional hearing format for expert witnesses to cross-examine or debunk one another.
As a result, the Charles Driscolls of the world are free to pollute hearings with junk science that can essentially never be effectively and timely challenged.
One possible solution is for scientific and technical portions of congressional hearings to be conducted by experts under the supervision of members, possibly under oath.
Whatever the solution, Congress must develop a means of hearing the whole of scientific truths - otherwise we will be at the mercy of half-truths.
Steve Milloy publishes JunkScience.com. Willie Soon is a Cambridge, Mass.-based physicist.