The Cardno ChemRisk View
Please contact Erin Hynds with any questions.
TSCA Stakeholder Meeting for Risk Assessment and Risk Prioritization- Will Your Business be Ready?
The U.S. Environmental Protection Agency (EPA) held two public meetings to gather input that will inform a proposed rule to establish a risk-based process for chemical prioritization (August 10), in addition to its process for conducting risk evaluations to determine whether a chemical presents an unreasonable risk of injury to health or the environment under TSCA section 6(b) (August 9).
By June 2017, EPA must decide on a risk-based screening process for evaluating new and existing chemicals. The previous “unreasonable risk” standard will be replaced by the “safety standard” for regulating chemicals, which will consider both hazard and exposure in a risk-based approach that is protective of human health and the environment.
During these meetings, stakeholders from government, private industry, academia, non-governmental organizations, as well as medical professionals, offered feedback regarding their suggestions and concerns. Cardno ChemRisk scientists, Dr. Denise Hill and Ms. Claire McMenamy, attended the meetings, and offer the following observations, as well as the selected comments, repeatedly offered by multiple stakeholders:
There has been research showing the presence of lead (Pb) and cadmium (Cd) in chocolate since 2001, although no evidence of harm from its consumption has been reported. For example, As You Sow, a consumer health protection organization, recently performed laboratory testing to measure levels of Pb and Cd on 50 different chocolate products available at retailers across California. The organization reported that 35 of the 50 chocolate products contained measurable levels of Pb and/or Cd. However, one should note that the presence of these metals in a food product alone is not sufficient to evaluate potential risks to consumers. The scientists at Cardno-ChemRisk presented work entitled “An exposure and health risk assessment of lead (Pb) in chocolate” at the annual Society of Toxicology meeting in New Orleans last week. To assess whether the ingestion of Pb-containing chocolate could pose a health risk to adults and children, our scientists used the EPA’s Adult Lead Methodology (ALM) and Integrated Exposure Uptake Biokinetic (IEUBK) models to predict the blood Pb levels (BLLs) of adults and children (aged 1-7) ingesting various amount of chocolate on a daily basis for 1 year. The results of this analysis demonstrated that in all cases, background Pb exposure was the primary contributor to estimated BLLs in children and adults, and Pb exposure from chocolate did not significantly increase estimated BLLs. Our findings indicate that simply reporting the Pb content of a chocolate product is not sufficient to evaluate health risk; the health risks of Pb in chocolate should be evaluated in the context of estimated background exposures using predictive blood Pb models. The SOT abstract of “An exposure and health risk assessment of lead (Pb) in chocolate” can be found here, along with the other abstracts that our staff presented. For further information, please contact Matt Abramson....
On November 3, 2015, the California Department of Public Health (CDPH) instructed consumers to avoid eating Rock and Dungeness crab caught off the California coastline, because of "dangerous" levels of domoic acid found in the animals (CDPH, 2015). Domoic acid is a naturally occurring neurotoxin produced by algae that can bioaccumulate in shellfish, and can be harmful to humans who eat the contaminated food (WDFW, 2015). Symptoms of domoic acid poisoning in humans, which can occur within 30 minutes to 24 hours after eating the contaminated seafood, include nausea, abdominal cramps, vomiting, seizures, permanent memory loss, and possible death (CDPH, 2015). According to the data presented in EPA's AcTOR database, domoic acid is dose-responsive in humans, with no effect at 0.2-0.3 mg/kg, mild (gastrointestinal) symptoms at 0.9-1.9 mg/kg, and most serious symptoms at 1.9 – 4.2 mg/kg (EPA, 2015).
Algae blooms off the Pacific coast are not uncommon, but this year's bloom is unusually large and persistent, because of particularly warm ocean water temperatures (Sommer, 2015). According the CDPH, "the conditions that support the growth of this [algae] are impossible to predict, and it is unknown when the levels found in crab will subside" (CDPH, 2015). Currently, California's action level for domoic acid in crabs is 30 ppm in viscera and 20 ppm in meat (CDPH, 2015). Samples from at least 72 crabs were taken and the data indicates that a "significant percent of samples exceeded one or both of these criteria", with one rock crab sample as high as 190 ppm and numerous other samples exceeding 100 ppm (OEHHA, 2015). According to the Office of Environmental Health Hazard Assessment (OEHHA), "consumption of Dungeness and rock crabs is likely to pose a significant human health risk as a result of high levels of domoic acid" (OEHHA, 2015).
Based on a simple dose calculation, if a 160 lb person (73 kg) consumed a pound of crab meat during a meal (0.45 kg) that contained 190 ppm of domoic acid, their domoic acid dose would be approximately 1.2 mg/kg. Similarly, if a 120 lb person (54 kg) or 215 lb person (98 kg) consumed this same amount of crab, their domoic acid doses would be approximately 1.6 mg/kg and 0.87 mg/kg, respectively. As referenced above, these doses of domoic acid can cause gastrointestinal symptoms. These results are based on a simple dose calculation, using the 10th, 50th, and 90th percentile weights for males and females over 20 years of age, and do not account for sensitive populations or pharmacokinetics parameters, such as absorption and distribution (EPA, 2011).
There was a previous outbreak in 1987 that involved mussels with domoic acid concentrations ranging between 31 to 128 mg/100 g, or 310 to 1280 ppm (EPA, 2015). The ingested dose by symptomatic patients was estimated to be between 60 and 290 mg domoic acid per person, which correspond to 0.8 to 4 mg/kg doses, which can cause serious symptoms according to the dose response data described above. Three people died from eating contaminated shellfish, and hundreds of others reported symptoms (EPA, 2015). Currently, there is no antidote for domoic acid poisoning, but supportive and symptomatic treatment is available.
As of November 6, 2015, the California Department of Fish and Wildlife has delayed the opening day for commercial Dungeness crab fishing, which was scheduled to open November 15, and closed the commercial rock crab fishery, which is open year round (CDFW, 2015).
CDFW (California Department of Fish and Wildlife). 2015. "Commercial Dungeness Crab Season Opener Delayed and Commerical Rock Crab Season Closed." November 6, 2015. Sacramento, CA: California Department of Fish and Wildlife. Retrieved from: https://cdfgnews.wordpress.com/2015/11/06/commercial-dungeness-crab-season-opener-delayed-and-commercial-rock-crab-season-closed/
CDPH (California Dept. of Public Health). 2015. "CDPH issues warning about Dungeness and Rock crabs caught in waters along the Central and Northern California coast." November 3, 2015. Sacramento, CA: California Dept. of Public Health. Retrieved from: https://www.cdph.ca.gov/Pages/NR15-082.aspx
EPA (Environmental Protection Agency). 2011. Exposure Factors Handbook, 2011 Edition. Washington, D.C.: National Center for Environmental Assessment, Office of Research and Development.
EPA (Environmental Protection Agency). 2015. Chemical summary: Domoic acid (14277-97-5). Retrieved on November 12, 2015, from EPA Aggregated Computational Toxicology Resource (ACToR) database, at: http://actor.epa.gov/actor/GenericChemical?casrn=14277-97-5
OEHHA (Office of Environmental Health Hazard Assessment). 2015. "Memorandum: Domoic Acid Threat to Public Health". Novemner 3, 2015. Sacramenta, CA: California Office of Environmental Health Hazard Assessment. Retrieved from: http://www.oehha.ca.gov/fish/pdf/110415domoicaciddungenesscrab.pdf
Sommer, L. 2015. "Why is an algae bloom closing crag season in California?" San Francisco, CA: KQED Science. November 5, 2015. Retrieved from: http://ww2.kqed.org/science/2015/11/05/why-is-an-algae-bloom-closing-crab-season-in-california/
Todd, E. C. 1993. "Domoic acid and amnesic shellfish poisoning-a review". Journal of Food Protection, 56(1), 69-83.
WDFW (Washington Dept. of Fish and Wildlife). 2015. "Domoic acid – A major concern to Washington State's shellfish lovers." Olympia, WA: Washington Dept. of Fish and Wildlife. Retrieved from: http://wdfw.wa.gov/fishing/shellfish/razorclams/domoic_acid.html