Delaware regulators revise “advisories,” say it’s OK to eat more Delaware fish.
A Feb. 20, 2018 press release gives us the usual positive spin. There’s some truth in it.
Levels of some waterborne toxins are dropping, as they should be, given that some very contaminated sites have been somewhat cleaned up. These sites tend to discharge toxins such as PCBs, dioxins, DDT, other chlorinated pesticides, and mercury, into waterways. Also, mercury from coal-burning power plants, “biomass” burners, and garbage incinerators falls out into the water. Fish take this water in through their gills, absorb some of the toxins, and these end up in their flesh. Eat these fish, and some of the toxins end up in you. If you are pregnant they end up in your baby. Coal burning in Delaware has decreased and, with much effort, we have generally been able to hold the line on incinerators and “biomass” burners.
But the picture is not quite so favorable as suggested by the DNREC press release.
There are, approximately, depending on how they are counted, 30 fish advisories for Delaware waters, including an overall advisory applying to all waters not otherwise listed, all finfish, and all contaminants. This advisory says not to eat more than 52 eight-ounce servings per year.
Approximately ten of these have been lifted or loosened. In some cases the guidance is now to eat no more than three servings per year rather than one. Or six servings per year rather than two. Or twelve servings per year rather than six.
In at least five cases, the guidance is still that “Women of childbearing age, and children should not consume any amount of these fish.” Children means less than six years old and the official serving for them is three ounces not eight.
So should you eat Delaware fish?
Delaware regulators are using a health risk breakpoint of one per one-hundred-thousand. In other words, factoring in all sorts of assumptions, this would be an acceptable lifetime health risk from eating fish. Above that, we get an advisory, below that, we don’t.
Delaware also uses an assumed 30 year exposure period, rather than the 70 year period commonly assumed to represent “lifetime” exposure. This cuts the assumed risk by 2.3 times. On the other hand, some assumptions used in Delaware could be more cautious.
Because these “human health risk assessments” do involve assumptions piled on top of assumptions they should be viewed with caution. On the one hand they may use “conservative” assumptions (few people would really eat that much fish …), on the other hand there may be more toxic substances in the fish than are tested for, and the cumulative/synergistic effects of multiple contaminants may be unknown. There may be unknown toxic effects even from known bad actors, or harm may occur at lower doses than assumed. Etc.
To be blunt about it, the Delaware Division of Fish and Wildlife is in the business of promoting fishing, and much of it’s revenues come from fishing licenses, etc. The Division receives federal funds for “restoration” efforts but this does not seem to include cleanup of contaminated habitat.
A technical document describing the Delaware fish advisory program is here. A Memorandum Of Agreement between the DNREC and the Division of Public Health has been in effect since 1993. We are still trying to get a copy. Our impression is that Public Health, unlike some in the DNREC, has never shown much interest in carrying out its responsibilities under this agreement. In particular, Public Health has not made much effort to put up warning signs. Example: The people promoting recreation along the Wilmington waterfront did not want the public to see signs indicating that the water is polluted and fish from the Christina River are unsafe to eat. So, when signs were finally installed they were put on bulkheads facing out into the river so nobody could see them except from boats. We understand that the DNREC is taking over responsibility for “signage” and possibly things will improve. (We didn’t get useful responses from the Division of Public Health.)
On the other hand, many argue that fish is a healthy food. The Fed 20th press release includes this:
“The improved water quality allowing people to eat more fish caught in local waterways is good news across the board,” said DHSS Secretary Dr. Kara Odom Walker, a board-certified family physician. “Consuming fish is an essential part of a healthy diet because fish contain so many key nutrients, are low in saturated fat and contain omega-3 fatty acids. The updated advisories will help Delawareans make good decisions for themselves and their families about the right kinds of fish to eat from our state’s waterways, as well as the right amount.”
It’s obviously absurd to imply that eating fish is “essential” to a healthy diet. But eating fish, in general, is likely healthier from a nutritional point of view than eating, say, beef or bacon. Healthier than rice and beans? Than a vegetarian or vegan diet? Opinions will vary.
What-to-eat guidance from government agencies depends as much–often more–on politics as on science. See, for example, this piece about how the political power of the meat industry, combined with the lack of integrity of academic institutions, keeps cancer-causing chemicals in bacon and sausage.
Red Clay Creek
One recently published report discusses renewed stocking of trout in the Red Clay Creek, a small creek long heavily polluted by industrial discharges in Delaware and Pennsylvania. This is worth a read for the light it sheds on DNREC’s thinking. Here’s the Executive Summary in full:
The Red Clay Creek in Southern Chester County, Pennsylvania and Northern New Castle County, Delaware has a long history of water quality problems. Fish contamination from legacy substances such as polychlorinated biphenyls (PCBs) and the pesticide DDT lead to the issuance of fish consumption advisories in the 1980s. These concerns also lead to the discontinuation of put-and-take trout stocking in this same time period. Conditions have improved to the point where advisories are now less stringent and there’s a desire to reintroduce trout stocking to the Delaware portion of the Red Clay. Before that can be done however, the Delaware Division of Fish and Wildlife, in collaboration with the Delaware Division of Watershed Stewardship, studied the uptake of contaminants in stocked trout in 2016 in the area that was historically stocked. The study objective was to assess if contaminants are taken up by the trout after being placed into the Red Clay and if so, how fast, and whether that uptake represents a significant health risk to anglers who may consume their catch. The management objective was to determine the feasibility of reintroduce trout stocking to the Red Clay Creek in Delaware.
Rainbow Trout directly from the hatchery had low concentrations of contaminants. When the hatchery trout were placed into the Red Clay Creek, they immediately began to accumulate and continued to accumulate several legacy contaminants including PCB, DDX, chlordane and dieldrin over the course of the study. The degree of accumulation was found to be a function of the concentrations in the water, streamflow, and the hydrophobicity of the contaminant.
Despite the accumulation of these contaminants, potential health risks to trout anglers can be kept low by moderating consumption (http://www.eregulations.com/delaware/fishing/fish-consumption-advisories/). This can be done by following the existing advice of no more than twelve (12) eight ounce meals of stocked trout per year which currently applies to other trout stocking waters in Delaware (except for the Christina River where the advice is half as much). Hence, it is feasible to return the Red Clay Creek to its former trout stocking status. More correctly, contaminant uptake alone does not prevent the Red Clay from once again joining the rotation of designated trout stocking waters in Delaware.
In addition to moderating consumption, another strategy to limit trout anglers from getting elevated exposures to contaminants in recaptured trout is to stock these trout a little later in the season. Because the trout, especially Rainbow Trout, cannot tolerate higher water temperatures, stocking them later shortens the window of time they can survive in the Red Clay and therefore limits the amount of chemical accumulation these fish will experience. This in turn limits potential exposure to trout anglers.
Is there a rational way to balance the claimed nutritional advantages of eating fish against the exposure to toxic contaminants? Clearly the DNREC (and, in theory, the Division of Public Health) feels it has found one. Do you agree?
Changing of the guard
Progress has been made on fish toxicity and two of the main contributors to this effort are retiring as of April 1st:
Rick Greene is retiring from the DNREC after a career of over 30 years. Rick has always been a key investigator of fish contamination and the sources for same.
Tom Fixlin has had a long career with the Delaware River Basin Commission and, before that, the US Environmental Protection Agency.
Rick and Tom’s work will be taken over by capable people, but both will be missed.
Toxins in commercial fisheries are regulated by the federal Food and Drug Administration under different rules.
What does seem clear is that only a few sites are responsible for a great proportion of the contamination and quicker cleanup of these would make a difference. These include the Amtrak repair facility in Wilmington, grossly contaminated with PCBs, DuPont’s former Edge Moor plant in Claymont, whose contaminants–PCBs and Dioxins–can be found for 70 miles up and down the Delaware River, DuPont’s (now Chemours?) former (?) Chambers Works site, and of course our good friends the Delaware City Refinery.
Another reality is that recreational and commercial fishers seldom lend much support to environmental cleanup demands.