Guidelines for the Management of Lead-Based Paint

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Appendix 2: Health Effects of Lead

Lead and its compounds are highly toxic, causing health effects which vary widely in their type and severity. Lead poisoning is a notifiable disease under the Health Act 1956.

The risk of lead poisoning only arises where:

the lead is available for biological uptake
exposure is such that a sufficient quantity of lead enters the body.

In the majority of situations, occupants and others are not normally exposed to the hazards associated with lead in paint. However, poor management of redecorating practices can create a risk for contractors, occupants, family pets and even those in neighbouring properties.

A2.1 Uptake and excretion

Since the effective controls on lead in foodstuffs and petrol, the uptake of lead in the domestic environment is predominantly from dust or fume inhalation, and the ingestion of paint fragments or dust (directly or via contaminated foodstuffs).

Ingestion of lead particles or lead-contaminated material is the primary route of intake for young children, and particularly preschool children who tend to eat, chew, lick or suck non-food items (including contaminated fingers).

By contrast, inhalation is the primary exposure for adults, as they tend to be more discerning about what they put in their mouth (although poor personal hygiene prior to smoking or eating may result in appreciable exposure via ingestion where hands are contaminated). Inhalation of dust typically arises during domestic cleaning and renovation activities.

Once in the body, lead may pass into the bloodstream or be excreted mainly via faeces and urine. The rate of uptake depends upon many factors, not least the chemical and physical form of lead. It is thus important to distinguish 'total lead' from 'bio-available lead'. Once in the bloodstream, lead tends to accumulate rapidly in hard tissues such as bones and teeth, from which it may be slowly released back into the bloodstream. Indeed, up to 95 percent of body lead burden may be found in bones.

The rate of release is largely governed by the blood lead concentration relative to that of the accumulation sites. Excretion of lead from blood and soft tissue takes around a few months, however only a few percent of the body burden of lead may be in the blood. Lead bound in the bone may take decades to eventually be excreted. Excretion from the body is primarily via urine. When the uptake rate exceeds the excretion rate, there is a net accumulation of lead in the body and the symptoms of lead poisoning will ultimately occur.

A2.2 Lead poisoning symptoms

The early stages of lead poisoning are non-specific and affect the gastrointestinal and nervous system. In later stages, symptoms may develop in the blood, kidneys, bones, heart and reproductive system and may, in extreme cases, result in death. One of the most important manifestations of lead exposure is developmental impairment in young children.

Symptoms of lead poisoning involving the nervous system can include:

mood changes such as depression or irritability
memory impairment
sleep disturbance
concentration difficulties
headaches
tingling and numbness in fingers and hands
muscle weakness and wrist drop (heaviness of limbs)
fits (rarely).

Symptoms of lead poisoning involving the stomach and intestine can include:

lack of appetite
nausea
diarrhoea
constipation
stomach pains
weight loss.

Other effects may include:

kidney damage and increased blood pressure
decrease in numbers and quality of sperm
miscarriage
anaemia.

If any of these symptoms are present, seek medical advice immediately, particularly if young children are affected.

Note: The above are reproduced from the Department of Labour publication Guidelines for the Medical Surveillance of Lead Workers.

Most young children suffering from elevated lead levels have no clear symptoms. The effects of mildly elevated lead levels can include reduced IQ, increased school failure, impaired neuro-behavioural development, cognitive deficits, irritability, and aggression. The general state of health may influence the severity of symptoms, as lead already in the body may be mobilised during pregnancy or due to health upsets, infections or excessive alcohol consumption. It should be noted also that lead can cross the placental barrier and affect the unborn child.

The intensity of exposure may vary greatly, and the effects of exposure may thus be acute (resulting from intense, short-term exposure) or chronic (resulting from prolonged low-intensity exposure).

As lead is a biocumulative toxin (a poison which can build up in the body), prolonged exposure to a low level of contamination can lead to an appreciable concentration in the body over time, sufficient to give rise to adverse health effects.

A2.3 Hazard, exposure and risk

Although lead is a poison, certain conditions must exist before the exposure to lead creates the risk of lead poisoning. The main factors which affect the degree of risk include:

personal habits/hygiene
the concentration of lead
its physical form (particle size)
its chemical form (bio-availability)
the intensity of exposure
the frequency of exposure
the duration of exposure
existing body lead burden
rate of excretion
body lead burden relative to body mass
personal health status
age of exposed person
diet of exposed person.

The risk may thus vary greatly, and the same source of lead can present different degrees of risk for different individuals. Furthermore, where lead does not constitute an immediate risk to health, it may have other long-term effects.

A2.4 Exposure routes

Exposure to lead in paints occurs at all stages in its life cycle, from mining the lead and using it as an ingredient in paint, through to its application, removal and weathering to dust. Exposures during this life cycle will vary dramatically by virtue of its physical or chemical form, and its location relative to people. These guidelines refer to exposures from lead paint removal and the resulting dust/fume.

A2.5 Children in the home

The primary exposure for young children is by ingestion of contaminated dust, soil or paint fragments. Preschool children are particularly susceptible to poisoning from lead-based paint because:

they may play on surfaces which contain contaminated dust, and transfer the contamination from hand to mouth
they may chew items containing lead-based paints
they may eat lead-contaminated material such as paint fragments or soil (a behaviour known as pica)
their small body mass means that even tiny amounts of lead can cause poisoning
they absorb proportionally more lead from their gastrointestinal tract than adults.

A2.6 Adults in the home

The primary exposure route for adults is inhalation of lead-contaminated dust. Although it is unlikely that adults will suffer serious poisoning as a consequence, pregnant mothers may pass sufficient lead to their unborn babies to cause the foetus to suffer lead poisoning.

Adults who may be exposed to dangerous amounts of dust include:

those involved in paint removal operations ('do-it-yourself' or commercial contractors)
those living where dust residues contain high lead levels arising from historical or ongoing paint removal operations
those involved in routine cleaning operations which raises dust into the breathing zone
those whose work or hobbies expose them to other sources of lead (eg, radiator repairers, users of lead solder, rifle shooters).

Table 7: Exposures to lead in the paint life cycle

Life cycle phase	Exposure category	Sources of exposure
Paint application	Occupational	Inhalation if sprayed.Ingestion (via poor personal hygiene in conjunction with eating or smoking).
	Environmental	Spillage to land.Liquid waste disposal from cleaning.
	Public	No significant exposure.
Paint in situ	Occupational	No significant exposure.
	Environmental	Accumulation of weathered paint fragments in soil.
	Public	Ingestion of weathered paint fragments.Ingestion of lead-contaminated soil.Inhalation of lead-contaminated house dust.Ingestion of lead-contaminated house dust (directly or indirectly).
Paint removal (and surface preparation)	Occupational	Fume from flame removal.Dust from paintwork removal (sanding, scraping, abrasive blasting).Ingestion via poor personal hygiene in conjunction with eating or smoking.
	Environmental	Solid waste accumulation on land.Liquid waste disposal from cleaning.Fume discharge from air.Accumulation on vegetation.
	Public	Ingestion of displaced paint fragments.Inhalation of fume/dust during and after removal.Consumption of vegetation with surface (dust) contamination.

A2.7 Domestic animals

Domestic pets tend to suffer from domestic lead poisoning more readily than humans because:

they are generally much smaller than humans
they wash and groom themselves by licking dirt from their fur
they tend to be less discerning in what and where they eat
they may eat food off the floor, or food which has been buried
they may chew items coated in lead-based paint.

Consequently, domestic pets (particularly cats and dogs) are often a first indicator of lead toxicity in the home. As with humans, lead poisoning symptoms are variable. Common indicators of lead poisoning include fits, behavioural change, deteriorating eyesight and gastrointestinal upset. It is not uncommon for domestic pets to die as a consequence of lead poisoning.

A2.8 Commercial painting contractors

Those whose work involves paint removal are likely routinely to encounter lead-based paint. Consequently, they must take steps to control even minor exposures, as they may be exposed frequently or for long periods.

Exposure primarily occurs during surface preparation, where the existing paint is either buffed or removed prior to repainting. The dust generated by such preparatory activities is close to the operator's breathing zone, and so is easily inhaled unless a filter respirator is worn. The greater the amount of dust generated, the greater the potential risk.

In addition to the personal risk for the operator, residents of the building must also be considered. Risks may occur where people are present during the work, or are exposed to lead dust from contaminated overalls and equipment.

A2.9 Others

As paint fragments, dust and fumes are easily blown away from the point of work, people in the vicinity of paint removal work may also be affected, including residents, observers and assistants. Under windy conditions, even neighbouring properties may receive sufficient dust from outdoor removal work to present a risk to their occupants.