Module 4: Metals And The Lung - Lecture

Classification of effects:

These can be divided into:

• Acute effects.
• Chronic airways disease: COPD, emphysema, asthma.
• Interstitial lung disease.
• Respiratory tract cancer.

Revise your understanding of the terms used in respiratory medicine. Note that COLD (chronic obstructive lung disease) is an alternative to COPD (chronic obstructive pulmonary disease).

Toxicology:

Metals form a wide variety of compounds (species) found in nature (for example, lead sulphide) or as a result of industrial activity. When burned they typically form metallic oxide fumes. They may be melted together with other metals to form alloys. Compounds may emerge in a variety of forms in smelting, welding or electroplating. Specific occupational exposures may thus not be obvious. Metals may also be incorporated into products not generally thought of as metallic, such as pesticides, fungicides and paint. They may contaminate other metals as a minor component, or form part of a complex non-metallic mineral such as asbestos.

In the body metals have a high capacity to bind to ligands, large molecules with reactive chemical groups on them such as -SH (sulfhydryl group). This binding assists carriage and storage in the body, but may the basis of the toxic effect, for example, inhibiting an enzyme, stimulating an allergic reaction, or even carcinogenesis.