BASIC PRINCIPLES IN OCCUPATIONAL HYGIENE Day 2

8 - BIOLOGICAL MONITORING AND HEALTH SURVEILLANCE

BIOLOGICAL MONITORING AND HEALTH SURVEILLANCE What experience to you have?

BIOLOGICAL MONITORING AND HEALTH SURVEILLANCE Health Surveillance is a generic term: any procedure undertaken to assess, review or monitor an individual’s health in order to identify or detect any significant change from normality. There are three reasons for health surveillance at work: –to ensure adverse health effects related to the work are identified at an early stage; sometimes this is statutory, e.g. in relation to work with lead. –to ensure continued medical fitness for specific tasks like diving or fire fighting –to promote general health.

BIOLOGICAL MONITORING AND HEALTH SURVEILLANCE Health surveillance techniques should be: Highly sensitive Specific in their ability to detect effects at an early and reversible stage. Safe. Preferably non-invasive and acceptable to the employee. Cost is also a consideration. Results of health surveillance should lead to some action of benefit to the health of employees.

BIOLOGICAL MONITORING Biological monitoring is an integral part of health surveillance and is the measurement of human tissues, fluids or behaviour in comparison with what is considered to be a normal range of values. –Medical confidentiality applies. –Can establish not only exposure but also its effect on an individual or group of people. Biological measurements can determine:- –the content of a toxic material or its metabolite in blood, urine and breath –Its effects on enzyme systems or metabolic pathways –Early reversible tissue change –Physiological changes Immunological changes.

Types of Measurements Urine –Cells (exfoliate cytology) - bladder cancer –Level of toxin e.g. mercury –Level of metabolite eg TCA (tricarboxylic acid) –Protein (especially kidney damage) –Bile (jaundice) –Sugar (diabetes) - relevant to shift work, public service vehicle (PSV) driving Blood –Full blood count and haemoglobin - lead, benzene, alcohol, work in the tropics –Serum (deep frozen) - baseline antibody levels in pathogen exposure –Liver function tests - alcohol, hepatotoxic chemicals –Renal function tests - kidney toxins –Toxin levels - e.g. lead –Metabolite levels - e.g. ALA.

Types of Measurements Skin –Appearance –Prick testing Breath –Dichloromethane and carbon monoxide exposure. Vision –Acuity tests e.g. lorry drivers, pilots etc. –Colour blindness tests e.g. civil aviation, railways, microscopy.

Types of Measurements X-rays –Chest x-rays are useful for conditions such as infection –Pneumoconiosis chest x-rays Neurological tests –Mental function –Nerve transmission –Handwriting tests (detects early tremors) Audiometry –The lowest intensity of hearing Lung function tests –Lung volume –Airways resistance.