Current legislation on heavy metals in foods and animal feeding-stuffs

Abstract

Quite contrary to what is generally assumed, there is not a great deal of specific legislation on food contaminants in the UK and we rely very much on the general provisions of the Food and Drugs Act. Therefore, this paper is concerned more with the UK philosophy and how various surveillance programmes, which we are responsible for, backup the UK philosophy. Statutory protection is afforded by the general provisions of the Food and Drugs Act 1955. Section I of the Act makes it an offence to add anythmg to food so as to render it injurious to the health of the consumer. Section 2 requires that food is of the nature, substance, and quality demanded by the purchaser, a term which has surely stood the test of time. Section 8 makes it an offence to sell unfit food. Section 4 of the Act gives Ministers the power to make regulations to reinforce these general provisions with more specific requirements. But, the only specific regulations applying to food contaminants are the Lead in Food Regulations 1961 (Great Britain: Parliament, 1961) and amendments and the Arsenic in Food Regulations 1959 (Great Britain: Parliament, 1959) and amendments. The impetus for these Regulations derived from serious acute poisoning episodes where food became inadvertently contaminated at high levels. These episodes involved the storage of acidic beverages in lead vessels and, in the case of arsenic, through the use of sulphuric acid to convert sucrose into glucose for brewing purposes. The sulphuric acid had been made from arsenical pyrites and was contaminated with arsenic trioxide. However, such episodes are now history. Heavy metal contamination of food The levels of heavy metal residues which have been found in food in recent times have only been detected by sophisticated developments in analytical methodology. Whereas ten, or even five years ago, the detectability and sensitivity of an analytical method was expressed in terms of milligrams, or micrograms, today, the nanogram and picogram are invoked with increasing frequency. Not surprisingly, the ease with which consumer concern can be aroused and both food manufacturers and regulatory authorities criticized increases with each succeeding report in a world striving unrealistically towards absolute purity. Much of this criticism may be ill-informed but regulatory authorities responsible for public health could be failing in their duty if they did not consider the implications for public health of both the contaminants themselves and levels at which these occur in food and the environment.

Electronic correlation strength of Pu

“…However, it should be noted that the relation between Z and bandwidth reduction is not the same in all materials, especially for weakly correlated broadband systems, which seem very different from strongly correlated materials like Pu. The simplest Hubbard-like Hamiltonian 45 to describe strongly correlated electron systems has a form…”

“…Much of our modern understanding of correlation effects has been developed using simple model Hamiltonians, especially the Hubbard model. 45 For metals, most of these approaches for strong correlations have focused on low-temperatures, 44 where the electronic-structure at the Fermi energy can yield a rich and diverse set of phenomena at low energy scales. In such a case, for example, specific heat or effective mass enhancements at the Fermi energy have often been used to characterize the strength of correlations.…”

Energy spectrum of extended Hubbard model with spin‐dependent hopping and related spin ladder model

“…he Hubbard model provides the most simple description of the correlation effects in narrow energy bands, such as metallic magnetism and the metal-insulator transition [1,2]. There is much interest in this model because of its applications to the study of high-T c superconductivity [3].…”