Lead poisoning

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Almost all people living in industralised societies, like New Zealand, will have some lead in their bodies. Lead is taken into the body through food, water and air. Most of this lead is not absorbed by the body. However, some people will develop health problems or lead poisoning if they are exposed to too much lead. If untreated, lead poisoning can be serious.

Where does lead come from?

Lead may come from a number of sources. These include old paint, petrol and some industries, eg, battery manufacture.

Before 1965 many house paints used in New Zealand had a high lead level (see the DHB Health Education Resource Centre for a pamphlet on re-painting). On many older houses, the old paint may still be in place; painted over or flaking off. When old paint is removed, the lead in it may settle in dust or soil.

Lead from petrol also adds to the amount of lead likely to be absorbed by the body. This is why it is being replaced by unleaded petrol.

Why are young children at risk of getting lead poisoning?

Infants and preschool children in contact with flaking paint, or contaminated dust or soil are particularly at risk of developing lead poisoning. This is because they often put their fingers and objects such as toys, which may be contaminated with dust or soil, in their mouths. Painted cots, rocking-horses, blocks or other toys that are old may be covered with lead-based paint. Young children absorb more of the lead they take in than older children and adults.

How does lead affect young children?

Contact with low levels of lead does not cause any obvious illness. However, if untreated it can affect the developing brain and nervous system and may impair development and later performance at school.

High levels of lead can cause symptoms such as vomiting, stomach pains, difficulty sleeping, constipation and loss of appetite. It is important to know, however, that there are many causes of these symptoms other than lead. If untreated, very high lead levels can result in more serious problems and lead to brain damage or even death. If you are uncertain if your child has been affected, ask your doctor for a blood test.

How does lead affect the unborn child?

As lead can be carried to the unborn child through the mother’s blood, exposure of the mother to lead through repainting, her type of work (eg, car radiator repair, painting, battery manufacture) or hobbies involving lead exposure (eg, leadlight window manufacture, indoor small bore rifle shooting) may mean the baby can be affected while it is still being formed. It can also cause premature birth or low birth weight, as well as later problems with development.

How can you protect your child from lead poisoning?

• Reduce exposure to sources such as lead-based paint and contaminated soil.
• Make sure your child has a good diet. Calcium and iron can help prevent your child’s body absorbing lead. Include at least two servings of milk products (equivalent to two glasses of milk) and one serving of lean meat, chicken or fish (equivalent to one small piece) each day.
• Make sure your children wash their hands before they eat.
• Take special care with home renovations. Seek advice about controlling leaded paint chips and dust if renovating older houses. If the house was built or repainted before 1970, assume that the paintwork is lead-based, unless shown by testing to be otherwise.
• Wash dummies and toys frequently, especially those used outside.
• Wet-dust floors, ledges, window sills and other flat surfaces at least once a week.
  

How is lead poisoning diagnosed?

Lead poisoning is diagnosed by measuring the amount of lead in the blood.

Treatment is available for lead poisoning

If you have any questions about lead poisoning, please discuss them with your nurse or doctor. Advice about how to protect yourself and your family from lead poisoning if your house is being repainted is available from the health protection officer in the Public Health Unit or a pamphlet is available from the DHB Health Education Resource Centre.

If blood is tested for lead and the level found is equal to or in excess of 15µg/dl (0.72µ mol/l), then the medical officer of health is notified if the source of the lead poisoning is from environmental exposure. (see Communicable Disease Control page for notification procedure). Where occupational exposure is suspected, please notify Occupational Safety & Health through Notifiable Occupational Disease System (NODS) network.

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