Tag Archives: Arsenic

China maintains ban on shellfish imports

Business and government officials involved in the lucrative geoduck export market got some bad news on Friday, when federal authorities released a letter they had received from the Chinese government.

Kitsap Sun photo
Kitsap Sun photo

The letter raises many questions — at least from a Chinese perspective — about how the U.S. regulatory system protects public health. The message from Chinese health authorities dashes the hopes of industry officials for a quick lifting of the Chinese ban on shellfish imports from the U.S. West Coast.

I wrote about this issue for Saturday’s Kitsap Sun (subscription). My story was picked up by the Associated Press and distributed widely. (If you don’t subscribe to the Sun, see The Columbian, Vancouver, for the AP version.)

Washington state has a proud reputation for protecting public health when it comes to shellfish, and the letter from China does little to dispel suspicions among those who think that China may have ulterior motives. After all, Chinese authorities have done nothing to limit the geographic scope of the import ban or even limit the ban to geoducks only.

A statement (PDF 114 kb) from the National Oceanic and Atmospheric Administration concludes that the letter contains about 20 separate requests for information about testing and safety.

You may wish to read the the letter from China’s General Administration of Quality Supervision, Inspection and Quarantine (PDF 150 kb). As translated, the letter includes this statement:

“We don’t not have a full understanding of the US regulatory system including the definition of sea region and management, the official monitoring on PSP and heavy metals and the responsibility among the relevant government agencies, and we have not conducted an on-site evaluation neither.”

The letter says the suspension of imports may be reduced to a specific area after certain questions are answered. It calls on the U.S. to develop an action plan for evaluation and outlines a review process, including a visit by an “expert team” from China to evaluate the geoduck inspection programs.

Officials at all levels in the U.S. say they are evaluating the questions posed in the letter and preparing a coordinated response.

Previous entries in Water Ways:

Jan. 9, 2014: Geoducks test OK, but what’s behind Chinese ban?

Dec. 24, 2013: Health officials to quickly test geoducks for arsenic

Geoducks test OK, but what’s behind Chinese ban?

Now it is up to Chinese officials to decide upon shellfish imports to their country, as uncomfortable as that may be for U.S exporters. I’ve begun to learn about international trade policies to better understand the confusing actions of Chinese health authorities.

As you’ve probably heard by now, officials with the Washington State Department of Health have concluded from a new round of testing that arsenic in geoducks from Poverty Bay presents no legitimate health concern. That seems to contradict findings from Chinese health authorities, who cited high levels of arsenic in Poverty Bay geoducks when they suspended shellfish imports from the U.S. West Coast.

Unfortunately, the Chinese have failed to reveal how they came to their findings, and they discarded all the geoducks used in their tests. Divers from the Washington Department of Natural Resources collected new geoducks from Poverty Bay, and state health experts conducted new tests. The findings were released Tuesday, and I covered that in some detail in a story published in yesterday’s Kitsap Sun (subscription). Also, check out Water Ways, Dec. 24, to understand the different types of arsenic.

USTR report

Results from the Washington state health lab showed that arsenic levels in all parts of the geoduck came in under the Chinese limit of 0.5 parts per million, except for the skin. Dave McBride, a toxicologist for the state health department, told me that cooks in both China and the U.S. blanch the geoduck to remove the inedible skin, so that’s not a factor.

But even if one consumes the whole geoduck, tests on the “whole body” found only one composite sample out of 12 that exceeded the Chinese standard. Of course, it would have been more convincing if none of the whole-body samples came in above 0.5 ppm.

A private lab also tested geoducks from Poverty Bay, and those results came in even lower. The differing findings probably resulted from the different methods used, Dave McBride told me. It might be wise to try to reconcile the differences and report the scientific uncertainty (possible range) represented by the two techniques.

Meanwhile, I’ve begun talking to experts on Chinese trade, who say it is not unusual for governments around the world to use alleged health concerns to gain a trade advantage.

As I reported in yesterday’s story, the U.S. Trade Representative, a presidential cabinet post, reported to Congress at the end of last year about what appeared to be unjustified health concerns blocking a variety of agricultural imports into China:

“In 2013, serious problems have remained for U.S. exporters, who are faced with nontransparent application of sanitary and phytosanitary measures, many of which have appeared to lack scientific bases and have impeded market access for many U.S. agricultural products.

“China’s seemingly unnecessary and arbitrary inspection-related import requirements also continued to impose burdens and regulatory uncertainty on U.S. agricultural producers exporting to China in 2013 … Products most affected in 2013 included poultry, pork and beef.”

Dongsheng Zang, a University of Washington law professor who specializes in Chinese trade, and Debra Glassman, faculty director of the UW’s Global Business Center, helped me understand the trade situation for yesterday’s story. Here are some of the key points I came away with:

  • Chinese officials don’t always base their decisions on the best evidence,, even though agreements under the World Trade Organization require them to do so. In 2011, China stopped imports of oysters from Washington state following reports of a few people getting sick from eating raw oysters from Hood Canal. Zang says Chinese officials based their actions only on “media reports.”
  • Import bans often come quickly and take a long time to resolve. That happens not just in China but in other countries and the European Union, especially when the dispute must be resolved by the World Trade Organization.
  • International agreements require that any import restrictions must be the “least-trade-restrictive” to protect the public, such as banning shellfish from specific bays where problems are identified, Glassman said.
  • The Chinese ban on U.S shellfish could be designed for a domestic audience inside China. “I can only speculate,” Zang said. “Food safety is a huge issue in China. It’s really hard to say whether this (geoduck ban) is about public health or domestic policy.”

An official in the office of the U.S. Trade Representative in Washington, D.C., told me (on background) that the office is watching this issue closely. If the shellfish ban develops into a full-fledged trade dispute, that office will become involved.

I realize that geoduck harvesters and government officials don’t want to accuse the Chinese of acting inappropriately. They just hope that the ban will be lifted without a drawn-out dispute. Meanwhile, those in the industry are losing millions of dollars by being shut off from their most important market for the giant clams.

Health officials to quickly test geoducks for arsenic

Shellfish and toxicology experts with the Washington State Department of Health are rushing to test new samples of geoducks from Poverty Bay near Federal Way. Poverty Bay is the apparent source of the geoducks that triggered a Chinese ban on the imports of all bivalves from the U.S. West Coast.

Photo: Washington Sea Grant
Photo: Washington Sea Grant

Since I wrote about this issue in Water Ways last Tuesday, state health officials have learned that arsenic — not paralytic shellfish poison — was cited by Chinese health officials as the cause of their concern in the Poverty Bay geoducks.

Past studies by state researchers have concluded that arsenic is not a health concern in shellfish taken from Puget Sound, based on sampling from some of the most polluted bays in the region. A letter (PDF 118 kb) sent last week from the U.S. Seafood Inspection Program to China’s health officials calls for China to lift its unusual ban. The letter cites a 2007 health assessment on arsenic in geoducks from Poverty Bay, where the giant clams were deemed safe to eat.

As a precaution, Washington Department of Natural Resources has closed the 135-acre Redondo Tract in Poverty Bay to shellfish harvesting until the Chinese ban can be resolved, according to a statement issued Friday from Public Lands Commissioner Peter Goldmark.

One of the complicating factors in dealing with arsenic in shellfish is that the organic forms (primarily arsenobetaine) are not toxic, yet they are far more prevalent than the toxic inorganic forms (arsenic III and arsenic V ).

It is far easier to measure total arsenic than to separate organic from inorganic forms, so researchers often make assumptions. To be extra safe, they have assumed for years that toxic inorganic arsenic is less than 10 percent of total arsenic. Now, they have begun to rely on more recent geoduck studies from Seattle’s Richmond Beach (PDF 327 kb) that showed the inorganic form of arsenic to be less than 1 percent of total arsenic.

Dave McBride, a toxicologist with Washington’s Department of Health, told me the Chinese were reporting levels of arsenic at 1.7 parts per million, but they failed to say whether that was total arsenic or inorganic arsenic. The Chinese health limit was reported as 0.5 parts per million inorganic arsenic.

It also makes a difference whether the whole geoduck was tested or just the edible parts. The skin, which is generally discarded when cooking, appears to concentrate more arsenic than other parts, but the levels still are not high enough to be a concern.

A 2002 study of shellfish from several polluted water bodies in Puget Sound (PDF 1.5 mb) found levels of inorganic arsenic in clams to fall in a range from 0.015 to 0.035 parts per million. A 2007 health assessment of geoducks from Poverty Bay (PDF 874 kb) found total arsenic levels ranging from 2.28 of 4.96 parts per million.

Assuming inorganic arsenic at 1 percent of total arsenic the maximum value is .05 parts per million for shellfish from Poverty Bay. That’s one-tenth the level of concern reported by the Chinese.

Initially, Poverty Bay was an issue because of two sewage outfalls in the area and the proximity to Tacoma’s former ASARCO smelter — even though most airborne pollution landing on the water gets well dispersed. But the formal health assessment allayed concerns about arsenic and other metals as well.

Arsenic always raises initial concerns, because its inorganic form is known to disrupt the metabolism of multi-celled organisms, including humans. Also, it has been known to cause cancer. Because inorganic arsenic levels in shellfish are normally low, no federal or state standards have been established.

In response to the Chinese ban, the Department of Natural Resources went out yesterday and collected new geoduck samples from Poverty Bay. The idea will be to present findings on both total arsenic and inorganic arsenic, thanks to more sophisticated analytical equipment at the Department of Health laboratory.

Three geoducks will be put together to create a composite sample. In all, two composite samples each will be associated with 12 different locations in the bay, according to McBride.

Edible geoduck tissue will be separated from the “gutball,” which may be prepared by some Chinese cooks, I’m told. If enough samples are available, the whole geoduck (minus the shell) may be tested as well, or possibly just the skin.

One long day of processing is planned for Thursday, and the samples will be run through analytical equipment over the weekend, McBride told me. A report on the findings can be expected next week.

For information about the China ban on shellfish, check out a fact sheet from the state’s Office of Shellfish and Water Protection (PDF 282 kb).