Nickel is a ferromagnetic transition metal sharing many properties in
common with iron and cobalt. Nickel
occurs naturally in the earth's crust, in various forms such as nickel
sulphides and oxides
generally resistant to corrosion especially in alloys-
therefore it is used in metal alloys e.g. stainless steeel and in various
electroplating processes
Sources of exposure:
Occupational exposures may arise in:
nickel miners, smelters and refiners
nickel alloy manufacturers
nickel platers
exposure to alloys e.g. in coinage
The following image shows a large industrial building within which nickel
refining took place:
Environmental exposures may arise from
nickel-containing alloys - such as in coinage in various forms of 'costume'
or 'fashion' jewellery
Soil/dust near nickel industries,
Hobbies and Related Activities
Metal working with nickel alloys
Health effects
Note: The health effects are highly dependent on the manner and degree
of exposure and on the exact chemical 'species' in which the nickel atoms
are present.The allergic effects tend to arise from
the Nickel cation Ni++, but it is not entirely clear which chemical
species is reponsible for the carcinogenic effects noted much more commonly
in the past. It is probable that a complex subsulphide may have been responsible
although high concentrations of soluble salts of nickel may have been important
too.
Health Effects include
Allergy of the skin to nickel - resulting in dermatitis.
The following image shows a case of nickel eczema (dermatitis).
Allergy of the lung to nickel - resulting in asthma
In certain circumstances of exposure in refining, there may be a risk of
cancer of the paranasal sinuses (close to the nose) and of cancer of the
lung. This risk has now probably been completely removed in most modern
plants.
Nickel tetracarbonyl - an intermediate in the Mond process for refining
nickel is very toxic to the lungs and heart.
Risk reduction
Note the following problems especially:
In refining - where there have been high exposures to complex nickel compounds
- and these could still be problematic unless adequately controlled.
The widespread use of nickel containing alloys in direct contact with the
human body in items of clothing and personal adornment, as well as in coinage.
Examples of Preventive Measures - avoiding hazards, and reducing risks
There have been significant improvements in the refining processes in the
developed world by way of steps to reduce exposure.
More widely steps should be taken to reduce exposure to nickel cations
by direct contact - either through reduction in nickel content of alloys
or in the use of alloys which are less likely to leach nickel following
skin exposure.
