Page 252 - IGC BOOK

• Blood sampling in which red and white cell counts are measured by automatic analysis
techniques and which enables early detection of anaemias and leukaemias.
• Urine tests measure concentrations of certain metals such as lead, cadmium and mercury,
and also the metabolites (products of chemical changes within the body) of certain organic
compounds, which can be used to assess exposure and absorption of those substances.
• Chest X-rays to screen people in dusty occupations where there is a risk of
pneumoconiosis, and establish accurate classification of the stages of the disease.
• Renal (kidney) function tests to identify damage to the liver cells themselves or to the
transport mechanisms to and from the liver, from occupational hepatotoxins (toxins which
can damage the liver), including organic compounds, antimony, arsenic and yellow
phosphorus; and infective agents such as serum hepatitis.
• Assessment of nerve conditions. Toxic damage to the nervous system may affect motor
and sensory function or brain function and cause impairment of consciousness. There is a
range of neurotoxins (arsenic, lead and mercury, carbon disulphide, methylene chloride,
toluene) which require environmental control and regular biological monitoring of people
who work with them. Tests include visual testing, nerve transmission tests
(electromyography, neuromuscular transmissions) and assessment of any changes in
intelligence or personality.

Biological monitoring takes into account routes of absorption, effects of workload, and
exposure outside the workplace. It can sometimes be a more reliable indication of health risks
than environmental measurements.

Additional Controls that are needed for Substance with Specific Effects

Carcinogens

Carcinogens are substances that have been identified as having the ability to cause cancer.
Examples of these include arsenic, hardwood dusts and used engine oils.
Genetic Damage

Substances known as mutagens have been identified that cause changes to DNA, increasing
the number of genetic mutations above natural background levels. These changes can lead to
cancer in the individual affected or be passed to their offspring's genetic material, for example
thalidomide and plutonium oxide.

Due to the serious and irreversible nature of cancer and genetic changes, an employer's first
objective must be to prevent exposure to carcinogens and mutagens. These substances
should not be used or processes carried out with them, if a safer alternative less hazardous
substance can be used instead. Where this is not feasible suitable control measures should
include:

ENSIGN| Unit IG2 – Element 7 – Chemical and Biological 47
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