Geoducks and Arsenic: DOH Says Geoduck Safe to Eat - Except for Skin

[Update 1/10: "In my opinion, it's the problem with the form and our inability to put more specific information on it." Bill Dewey, Taylor Shellfish explaining why the "debacle" resulted after  Chinese testing showed arsenic and paralytic shellfish poisoning in geoduck above levels they consider safe. Or was it political? If the Chinese wanted to make a political point they could have made a far stronger point by ordering Airbus jetliners or timber from Russia. What the shellfish industry may want to consider is that testing shellfish in the US could be improved, not only for the Chinese but for US citizens as well. Anyone who has suffered through vibriosis contracted from from Puget Sound's oysters would most likely agree.]

[Update 1/7 5PM: Added table showing levels of inorganic arsenic found in geoduck samples. Shown is a "whole" sample (D1) which was above China's .5 ppm*. This was not mentioned in the 1/6/2014 DOH press release below, nor were the higher individual samples (e.g., B2 being ~1.75 ppm vs the 1.175 in the table below).

*Note: EarthFix has reported the World Health Organization is said to be considering setting safe levels for inorganic arsenic in food in the .2-.3ppm range in 2014. In addition, they also noted this: “I’d be nervous after a big rainfall event,” said Kathy Cottingham, a professor in the Department of Biological Sciences at Dartmouth College who studies arsenic exposure and human health. “With soils that contaminated you need to worry about the episodic events of a big rainstorm or snowmelt causing pulses into the water.”

(EarthFix/Anthony Schick)

2014 high level of inorganic arsenic in skin not considered significant
The Washington Department of Health has released test results from geoduck harvested from the Poverty Bay area, off of Federal Way. Test results showed the skin to have levels of inorganic arsenic over 2 times higher than the .5 ppm (parts per million) level which China is concerned about. As it is was assumed the skin is not consumed by the Chinese this number was not considered significant by the Department of Heath. Overall, test results indicate a range from 1.175 ppm in the skin to .063 ppm in the "meat."

Inorganic Arsenic Test Results

January 6, 2014

(Chinese level of concern >.5ppm)

(click here for 2014 release)

 

 

2007 inorganic arsenic assumption

In 2007 inorganic arsenic was not specifically tested for. Instead it was estimated to be 1% of the total arsenic level found. In the report they noted inorganic arsenic in shellfish can be as high as 19% of the total arsenic (page 9). Based on testing by the Suquamish Tribe an assumption was made that inorganic arsenic was 1% of the total arsenic found (page  9). The 2007 test results below were from the neck with the skin removed (page 8). The skin was not tested.

 

Inorganic Arsenic Results from 2007

(Note: mg/kg are equivalent to ppm,

and only geoduck necks were tested)

(click here for 2007 report)