Sep 29, 2010 – On April 20 2010, the oil spill in the Gulf of Mexico saw an estimated 207 million gallons of oil released. The water and seafood product analysis offered by SGS allows for measurement of the impact.
With the shrimp harvesting season now underway in the Gulf of Mexico, an improvement in the seafood situation can be observed, leading to hopes within the shrimp industry of a significant rebound in production. While the National Oceanic and Atmospheric Administration (NOAA) had (in consultation with Gulf states Alabama, Florida, Louisiana, Mississippi and Texas) originally closed roughly one third of the gulf, only 23% of gulf waters were closed in August to the harvesting of seafood.
Concerns around Safety of Seafood
Oil related toxins known as polycyclic aromatic hydrocarbons (PAHs) are of key concern to consumers, retailers and those in the food industry buying gulf seafood. High levels of these chemical contaminants may accumulate in seafood products exposed to oil, with the possibility that PAHs result in illness among those who consume seafood. A related concern is that consumers may also be exposed to cancer causing contaminants or contaminants that cause neurological damage. These outcomes are possible if seafood absorbs petroleum-based substances.
The likelihood of contamination of seafood depends on the way in which species are exposed to contaminants as well as the nature of the species.
Species that are filter feeders will absorb oil when exposed to it, whether exposed while the oil is dispersing or breaking down. Clams, oysters and molluscs come under this category. Alternately, crustaceans will tend to absorb oil through their diet, including both contaminated plant and animal materials. The risk of absorption will increase for those crustaceans, including shrimp, which are found in shallower waters.
Some species passing through contaminated waters will absorb oil through the gills or gut. For example, predatory finfish will absorb oil and PAHs in this way, as well as through feeding on contaminated species.
In order to clean up the spill, BP is using oil dispersants. Even though these substances generally dissipate within a few days, and are regarded by the Environmental Protection Agency (EPA) as being less toxic than oil, it remains unknown as to whether they have any long terms effects on sea life.
Moves Being Made to Ensure Safety
The NOAA has put in place measures to ensure that contaminated seafood products are not sold to consumers. The NOAA has heightened testing measures, including sensory evaluation by fish sniffers of potentially contaminated product. NOAA vessels collect these products, producing samples that are typically tested by NOAA scientists for PAH contamination via Mass Spectrometer (LC/MS) and Liquid Chromatograph.
Besides product testing by the NOAA, steps have also been taken by the US Food and Drug Administration (FDA) to safeguard consumers. Industry producers have been notified that Hazard Analysis Critical Control Point (HACCP) plans must include measures for contaminants such as PAHs. This requirement comes as part of Code of Federal Regulations (CFR) 123 regulation 21, designed to safeguard against the sale and consumption of potentially toxic seafoods. In addition, under 21 CFR 128.28, all shellfish (molluscs) must be tagged, and suppliers are banned from shellfish harvesting within closed areas. Tagging of shellfish enables identification of harvesting dates and locations, and records the license details of the harvester.
Both water and seafood products can be tested for oil and related contaminants. The presence of PAHs and oil can be detected using instrumentation including both Liquid Chromatograph coupled with a Mass Spectrometer (LC/MS), and Gas Chromatograph coupled with Mass Spectormeter (GC/MS).
Source: SGS Group
