Canned foods, lead

In addition to their concern regarding spray residues of the lead arsenate and organic types, canners whose fruits are sprayed with lime sulfur have reason for concern over the presence of sulfur in their canned products. The presence of elemental sulfur or simple compounds of reduced sulfur in canned foods, especially in those products having an acid character, is objectionable, not only because it may be the source of sulfide flavor and staining, but also because it may actively accelerate the formation of hydrogen by the corrosive action of the product on the container. 

The total number of different anthocyanins reported to be isolated from plants was 539. However, the number of anthocyanins found in foods is much smaller. Although a large number of papers were published regarding anthocyanin composition in several foods, investigators in most studies used only chromatographic and chemical behaviors as bases for identification. In this chapter, we considered only papers in which identification was based at least on mass spectrometry (MS). In fact, the use of only MS and UV-visible information can easily lead to misidentifi-cation as the following example shows. 

During the media blitz that followed, Patterson urged the public to buy Chicken of the Sea tuna because the Van Camp Sea Food Company s molded steel cans were lead-free. With characteristic bluntness, Patterson lambasted a host of government laboratories from the Environmental Protection Agency and its Bureau of Foods to the National Marine Fisheries Service and the Food and Drug Administration (FDA). Asked if any other laboratories agreed with his findings, Patterson declared loftily that scientific questions are not determined by majority vote. 

Children are more vulnerable to lead poisoning than adults. Children are exposed to lead all through their lives. They can be exposed to lead in the womb if their mothers have lead in their bodies. Babies can swallow lead when they breast feed, or eat other foods and drink water that contains lead. Babies and children can swallow and breathe lead in dirt, dust, or sand while they play on the floor or ground. These activities make it easier for children to be exposed to lead than adults. The dirt or dust on their hands, toys, and other items may have lead particles in it. 

At one time canned foods were a significant source of lead because of poor-quality solder joints in the cans. High-acid goods, such as tomatoes, would leach lead from the cans. Finally, contamination of drinking water with lead occurs primarily from lead solder joints or old fixtures and occasionally lead pipe was used to bring water to a home. As with many metals, lead was used in a number of remedies, some of which are still available and used by some ethnic groups. 

Residues can also lead to regulatory action under the US federal food and drug laws. Producers whose animals are found to contain illegal drug residues may be held legally responsible for the shipment of adulterated food in interstate commerce. In some cases, prosecution of offenders under these rules will result in monetary fines and possible jail sentences. These potential penalties are in addition to the economic difficulties encountered because of the market restrictions. 

The presence of elements known to have adverse health effects in humans such as lead and arsenic is obviously undesirable in food. Environmental sources are the main contributors to contamination of food with most metals and other elements. Some elements (e.g. arsenic) are present naturally but the major sources of other elements (e.g. lead) in the environment are from pollution from industrial and other human activities. The presence of metals and other elements in food can also be the result of contamination from certain agricultural practices (e.g. cadmium from phosphate fertilisers) or manufacturing processes (e.g. tin in canned foods). 

Jermy, T., Can predation lead to narrow food specialization in phytophagous insects , Ecology, 69, 902, 1988. 

Lead-based paint— Present on many surfaces in homes not recently rebuilt or remodeled Lead pipes— More common in older homes Lead solder— On pipes and water heaters Enameled or ceramic pots and dishware—Improper glazing can leach lead into foods Paper wrappings— Holiday paper and party decorations (10 g/kg)... 

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