Toxicity to humans
Luzenac
Luzenac, as a major talc producer, is conducting epidemiological studies of employees in its major European operations and the results are published in peer reviewed literature. This information is being provided to Government bodies such as the US National Toxicology Program, US Dept of Health and Human Services. This research is conducted under the auspices of a French Government research institute. The International Agency for Research on Cancer, part of The World Health Organisation (WHO), commended Luzenac for its decision to publish its work in the open literature, saying the open policy will advance the cause of occupational health protection to everyone's benefit.
Luzenac has also been working with:
- The Cosmetic, Toiletry, and Fragrance Association on sponsoring experts to review studies considering talc as a risk factor in ovarian cancer; and
- Independent mineralogists on the potential occurrence of asbestos (in any of its six forms) in talc deposits and the analytical determination of asbestos at very low concentrations in mineral ores.
Copper Group
Copper is essential to life. Low intakes produce deficiency diseases and high intakes produce toxicity. All animals have a variety of systems to manage their copper level, ensuring health over a range of copper intakes. While there has been extensive research into the copper daily intake ranges that are compatible with good human health there is less known on the effects of different copper intakes and why some individuals may be more or less tolerant to a large range of copper intake.
The International Copper Association, of which Rio Tinto is an active member, is working to develop:
- An understanding of how copper is regulated by the body;
- What markers can be used to establish the copper level of an individual;
- What concentration is safe in the diet;
- What level of copper in drinking water causes no effect; and
- If some individuals are more sensitive than the majority because of their age or genetic make up.
Rio Tinto Borax
One of the primary goals of the Borax programme is to produce animal data that can be used to demonstrate that boron is a nutritionally essential mineral. To do this requires data regarding the evidence of adverse effects when boron is absent from the diet, as well as evidence of a biochemical function that utilises boron. One common finding of past studies was that boron appeared to maintain cell membrane function, which is particularly important for rapidly dividing cells. A number of research programmes are being sponsored including:
- Determination of the effects of low boron concentrations on mammalian embryonic cell membrane function and integrity at the University of California at Davis;
- Determination of the cellular and biomolecular mechanisms of boron interaction at University of California at Los Angeles; and
- Molecular techniques at the University of Missouri to identify and characterise boron transport proteins utilised by yeast, which have already been shown to be dependent on boron for growth. Identification of boron specific proteins themselves will demonstrate boron essentiality, while determination of the sequence of genes encoding these proteins will allow for the discovery of similar genes in a wide range of different organisms.
Rio Tinto Borax has instigated unique research in humans on the nasal perception and feel of borate and other dusts, both non irritants and known irritants, at the University of California in San Diego. The aim of the study is to provide credible human data to assist in setting correct occupation exposure levels (OELs) for borates.
Rio Tinto Borax has also summarized the world's literature on the effects of borates on aquatic organisms. The data is being used to help complete a boron risk assessment for the European Union.
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