With Louisiana's fall shrimp season kicking off and Alabama's coastal waters reopening for recreational and commercial fishing, there's concern about seafood coming from the Gulf. So what's really happening? How fearlessly should we approach those bites of shrimp?

An Associated Press story in The Washington Post offers a fresh explanation of Gulf seafood testing, presenting useful questions and answers about the testing process and what inspectors are looking for (going well beyond the now-famous sniff test). Learn about the specific chemicals (such as polycyclic aromatic hydrocarbons, a.k.a. PAH's) that, in the wake of the oil spill, taint animal life in the Gulf—as well as how inspectors decide to reopen fishing waters and why oysters are taking the longest time to recover:

Q: What are PAHs?

A: They're common pollutants from oil, vehicle exhaust, wood-burning fires and tobacco smoke. They can be in food grown in polluted soil and form in meat cooked at high temperatures. In fact, NOAA research found that Alaskan villagers' smoked salmon, a staple food, contained far more PAHs than shellfish tainted by the Exxon Valdez spill.

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Q: With so much oil in the Gulf, how could fish emerge untainted?

A: Commonly consumed fin fish - like grouper, snapper and tuna - rapidly metabolize those PAHs. That's been known for years and tracked during other oil spills, and the reason that fishing is being allowed first in reopened waters.

Consider the PAH naphthalene. The safe limit is 3.3 parts per billion. The highest levels found in recently reopened waters off the Florida panhandle were well below that, 1.3 ppb, mostly in red snapper.

Read the full story at The Washington Post.