Guidelines for the Management of Lead-Based Paint
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2 HAZARDS OF LEAD
2.1 Introduction
Lead in paint, and the contaminated dust and soil it generates, is now recognised as a significant source of lead toxicity, and is an important occupational and public health issue. The prevention of health effects from this source is specifically addressed in this guideline.
Lead is both a poison and a persistent environmental pollutant, and is widely distributed throughout the built and natural environment. It causes a variety of symptoms, some of which are indistinguishable from other causes, and may ultimately result in death. Lead affects the developing brain and nervous system, and can result in mental retardation of young children. The health effects of lead are discussed in more detail in an appendix to this guideline.
Possible sources of lead in and around the New Zealand home might include:
- dust and fragments from lead-based paint
- old lead plumbing and leaded solders
- nearby lead-related industry (eg, smelter, battery manufacture)
- lead dust-contaminated work clothing
- some hobbies and crafts (including fishing, modelling, leadlighting, and shooting)
- tinned food from overseas (from lead in solder)
- lead-contaminated soil on vegetables and fruit
- some alternative medicines and cosmetic products
- glazes on commercial or hobby pottery
- lead in food and beverage containers (eg, pewter and crystal)
- radiator repair work
- exhaust fumes and lead-contaminated dust beside busy roads (although with the removal of lead from fuel by 1996 airborne lead from exhaust emissions has virtually disappeared, however lead deposited in dust and soils may still be present).
As lead poisoning can cause a variety of health effects, including death, lead can clearly be considered a 'significant hazard' as defined by the Health and Safety in Employment Act 1992 (ie, exposure to lead may result in 'serious harm' as prescribed in the First Schedule).
Where there is a risk of lead poisoning arising from a work activity or workplace, the hazard must be eliminated. Where elimination is not practicable, it must be isolated to control exposure to the hazard. If this is impracticable, the risk must be minimised.
Controls on the use of lead in industry as an insecticide, paint additive, petrol additive, and a means of sealing tin cans have been successful in reducing public and occupational exposure to lead. However, this has raised the relative importance of lead in paint on old buildings being renovated.
2.2 Lead in paint
The domestic paints available today contain only very small quantities of lead, and are unlikely to be considered to be a hazard. However, the lead content of paints used in the past was generally much higher, and old paintwork can, under certain circumstances, present a risk.
Since redecoration generally covers earlier layers of paint, lead-based paint is likely to be present in most domestic properties, although not necessarily in the surface layer. When overcoating by a lead-free surface layer, the risk to health is negligible unless the surface deteriorates or is removed. Although properties built after 1970 are generally considered to have low lead content paints, there is evidence that some properties built between 1970 and 1980 were still being painted with lead-based paints.
Several paint removal methods, particularly power sanding and dry abrasive blasting, generate high concentrations of dust and fumes which are dissipated widely. A number of studies have established that exposure to lead from interior and exterior paint removal can be hazardous and can give rise to lead poisoning. The hazard may affect those doing the removal work, those in the vicinity at the time, or those exposed to dust and fragments long after the work is completed.
In 1984, the Building Research Authority of New Zealand (BRANZ) estimated that 251,000 properties in New Zealand had lead-based paint on them, and that each year up to 5,000 properties undergo work to remove paint containing lead pigments.
Primarily, the concern has been over lead in exterior paints, given their historically high lead content. However, interior paints used on fixtures, fittings, and building components such as doors and windows may also contain appreciable quantities of lead.
Properties where lead-based paint coatings are flaking or dusting present a potential source of elevated background levels in house dust and soil, and hence an increased risk of exposure for occupants. Young children and the foetus are particularly affected by lead poisoning and, in many cases, their condition goes unnoticed.
2.3 Hazard management
The Health and Safety in Employment Act 1992 requires employers to take all practicable steps to ensure that their work activities do not harm their employees or other people. Management of the occupational health hazards associated with paint removal work is thus largely the responsibility of the contractor.
The function of health and safety inspectors from Department of Labour is to ensure that the identification and management of occupational lead exposure is carried out effectively by employers in accordance with the provisions of the Act.
Management of the public health hazard arising from lead-based paint in the home is a more complex issue, but may be the responsibility of both the owner and occupier, dependent upon the circumstances. Health protection officers (HPOs) from the public health units of the District Health Boards will assist with the identification of lead paint and provide advice on the management of non-occupational lead exposures.
A list of addresses and contact people for the Department of Labour and public health service providers is included at the back of these guidelines.
Effective hazard management requires hazards to be identified, assessed and managed, and then checked to ensure the method used is effective. The remainder of this guideline details how this may be achieved. The emphasis throughout is on preventing problems associated with the removal of lead-based paint.