Environmental Engineering Reference
In-Depth Information
Open self-service food counters, salad bars, or buffets require a physical barrier
such as a canopy or guard that will effectively prevent or minimize contamination
by persons assisting themselves to the displayed food. In any case, the potentially
hazardous food should be held either at or above 140
◦
F(60
◦
C) or at or below
45
◦
F(7
◦
C) at all times. Displayed foods remaining should not be reused.
Since food service in private institutions, including churches and nonprofit and
fraternal organizations, have been implicated in numerous foodborne outbreaks,
special educational material should be developed incorporating the principles
listed above and distributed to affected organizations. Caterers should be under
special surveillance and permit.
Sandwiches containing potentially hazardous foods that remain unrefrigerated
for more than 2 or 3 hours at room temperature can support the growth of bacteria
that could lead to a foodborne disease outbreak. Prior refrigeration, or freezing
where appropriate, and consumption within 4 hours will minimize the hazard.
Cheese, peanut butter and jelly sandwiches, salami, bologna, and hard-boiled
eggs will keep better. Canned meats and poultry also keep well. Commercial
mayonnaise (pH below 4.1 - 4.6) will inhibit the surface growth of salmonellae
and staphylococci on food, but the pH of all the ingredients or mass of the food,
such as egg, meat, chicken, or potato salad, must be reduced to inhibit bacterial
growth in the food. Vinegar and lemon juice can accomplish the same objective,
provided the food ingredients do not neutralize the acidity of the mixture. The
salads should be kept refrigerated. The guiding principles should be hygienic food
preparation practices, proper cooking, and
prompt refrigeration
of potentially
hazardous foods if the food is not immediately.
Mercury Poisoning
Mercury poisoning in humans has been associated with the consumption of
methylmercury-contaminated fish, shellfish, bread, and pork and, in wildlife,
through the consumption of contaminated seed. Exposure to mercury may also
occur from household sources, including certain antique items such as clocks or
thermometers.
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Short-term exposure to high levels of mercury can cause lung
damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate,
skin rashes, and eye irritation. Exposures to mercury vapor at high levels can
permanently damage the brain, kidneys, and developing fetuses. Mercury expo-
sure is of particular concern for fetuses, infants, and children, and for persons
with medical conditions that might be worsened by exposure to mercury, such
as conditions of the nervous system, kidneys, or heart and vascular system.
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,
75
Fish and shellfish poisoning occurred in Japan in the Minamata River and
Bay region and at Niigata between 1953 and 1964. Bread poisoning occurred
as a result of the use of wheat seed treated with a mercury fungicide to make
bread in West Pakistan in 1961, Central Iraq in 1960 and 1965, and Panorama,
Guatemala, in 1963 and 1964. Pork poisoning took place in Alamagordo, New
Mexico, when methylmercury-treated seed was fed to hogs that were eaten by
a family. In Sweden, the use of methylmercury as a seed fungicide was banned
