_____________________________________________________________________________________________________________________ 

Memorandum 

Date: November 28, 2022 

Subject: Cadmium (Cd) in Roasted Organic Seaweed Snack 

Re: CMS Case # 646463, Task # 679193, Private laboratory sample # 3824380 

CMS Case # 646470, Task # 679195, Private laboratory sample # 3868851 

From: Jacqueline Heilman, Ph.D. ______________________ 

Contaminant Assessment Branch (CAB) (HFS-005) 

Division of Risk and Decision Analysis (DRDA), Office of Analytics and Outreach (OAO) 

Judith Spungen, M.S., R.D. ___________________________ 

Exposure Assessment Branch (EAB) (HFS-005), DRDA, OAO 

To: Quynh-Anh Nguyen, Ph.D. 

Division of Plant Products and Beverages, Office of Food Safety (OFS) (HFS-317) 

As requested by OFS, DRDA evaluated the safety of exposure to Cd in two samples of Kirkland 

brand Organic Roasted Seaweed Snack (seaweed snack). Samples of the seaweed snack (samples 

# 3824380 collected in Pearl City, HI, and # 3868851 collected in Rosedale, MD) were analyzed 

by a private laboratory, Certified Laboratories, and found to contain 1.280 and 0.750 mg/kg 

(μg/g) Cd, respectively. Kansas City Elements Laboratory reviewed the data package for sample 

# 3824380, and Southwest Regional Laboratory reviewed the data package for sample # 3868851, 

and both samples were found to be acceptable with borderline results. 

DRDA Conclusion 

DRDA concludes that exposure to Cd from consumption of seaweed snack sample # 3824380 is 

likely to be a health concern for children (MF 0-6 y), but not for the general population (MF 2+ 

y). Cd exposures from consumption of seaweed snack sample #3868851 are not likely to be a 

health concern for children (MF 0-6 y) or the general population (MF 2+ y). 
 

 

 

 

 

 

 

 

 

 

 

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Consumption and Exposure Estimates 

DRDA generally relies upon results of the National Health and Nutrition Examination Survey 

(NHANES), What We Eat In America (WWEIA) component for estimating dietary intakes of foods 

and for estimating contaminant exposures from intake of those foods. However, the number of 

WWEIA/NHANES respondents reporting dried seaweed consumption is too low to assure 

statistical reliability of estimates. Seaweed snacks generally are packaged as 5 g single servings, 

and DRDA generally estimates upper-level daily intake of seaweed snacks assuming consumption 

of one 5 g serving per day. The seaweed snack that is the subject of the current case is sold in 17 

g packages, with a labeled serving size of 1/5 package, or 3.4 g. However, for consistency, DRDA 

estimated upper-level daily intake of the dried seaweed snacks to be 5 g/day, for both adults and 

children. 

Estimated Cd exposures from consumption of the seaweed snack are shown in Table 1. 

Table 1. Estimated exposure to Cd from consumption of seaweed snack. 

Contaminant Population 

Contaminant 

Concentration 

(μg/g)

Estimated UpperLevel Chronic 

Consumption of 

Seaweed Snacka (g/kg 

bw/day)

Estimated UpperLevel Chronic 

Contaminant 

Exposure from 

Seaweed Snackb 

(μg/kg bw/day)

Cd (sample # MF 0-6 y 

1.280 

0.31 0.40 

3824380) MF 2+ y 0.07 0.09 

Cd (sample # MF 0-6 y 

0.750 

0.31 0.23 

3868851) MF 2+ y 0.07 0.05 

a Estimated based on serving size of most single packages of seaweed snacks. Intakes were converted to g/kg 

bw/day using body weights of 75.4 kg for the general population and 16.1 kg for children (based on average body 

weights measured in NHANES 2017-2018). b Concentration in sample (μg/g) * upper-level consumption (g/kg bw/day) = estimated total exposure (μg/kg 

bw/day) 

Safety Assessment 

Cadmium (Cd) 

Cd is an accumulative toxic element with a long biological half-life between 10 to 33 years in 

humans. Therefore, the toxicity of Cd generally results from chronic exposure. For the general 

population who are non-smokers, diet is the major source of Cd exposure. Chronic exposure to 

Cd in food may lead to its accumulation in the kidney (generally regarded as the most sensitive 

target for Cd toxicity), and this can cause renal tubular dysfunction and damage over time (WHO, 

2011). EFSA has established a tolerable weekly intake (TWI) of 2.5 μg/kg bw/weekly for Cd,

corresponding to 0.36 μg/kg bw/day (EFSA, 2009). The TWI is based on a meta-analysis of human 

The information contained in this document is confidential and distributed for internal purposes only. 

The content of this document is pre-decisional and deliberative. 
 

 

 

 

 

 

 

 

 

Page 3 of 3 pages 

epidemiological studies assessing the relationship between urinary Cd and beta-2-microglobulin 

levels and a toxicological model to convert urinary Cd to dietary Cd exposure. 

As shown in Table 1, Cd exposure from regular consumption of seaweed snack sample # 3824380 

for children (MF 0-6 y) is above the TWI, adjusted for daily exposure, and is therefore likely to be 

a health concern for this population, but not for the general population (MF 2+ y), for which Cd 

exposure resulting from consumption of seaweed snack sample # 3824380 is below the TWI 

adjusted for daily exposure. Cd exposures resulting from consumption of seaweed snack sample 

#3868851 are below the TWI adjusted for daily exposure for children and the general population 

and are therefore not likely to be a health concern for either of these populations. 

References 

European Food Safety Authority (EFSA) (2009). Cadmium in Food. Scientific Opinion of the 

Panel on Contaminants in the Food Chain. EFSA Journal 980, 1-139. 

World Health Organization (WHO) (2011). Cadmium. Safety evaluation of certain food additives 

and contaminants. WHO Food Additives Series, No. 64/FAO JECFA Monographs 8. World Health 

Organization, Geneva. Available at 

http://apps.who.int/iris/bitstream/handle/10665/44521/9789241660648 eng.pdf;jsessionid=D 

96891CABDCBCF63BE8F57D7CA615E2C?sequence=1 

Accessed 11/28/2022. 

The information contained in this document is confidential and distributed for internal purposes only. 

The content of this document is pre-decisional and deliberative.