Lead

Lead absorption at home is a condition which is notifiable to the medical officer of health under the Health Act 1956.

People living in an industrialised environment may have some lead in their blood. Lead gets into the body through food, water, soil and air.

Lead is not absorbed by the body. Once in the bloodstream it tends to accumulate in hard tissues such as bones and teeth, from which it may slowly be released back into the bloodstream. The rate of release is dependent on the concentration of lead in the bones.

When the uptake rate is faster than the excretion rate, there is a net accumulation of lead in the body and that is when lead poisoning occurs.

Possible sources of lead in New Zealand homes might include:

  • Lead-based paint around houses built before 1970
  • In older houses, old paint may still be in place, painted over or flaking off
  • In the process of removal, lead may settle in dust or soil
  • In hobbies that involve the use of lead for example soldering, welding or other activities involving cutting or melting
  • Casting lead models
  • Applying glaze to ceramics of pottery (hobby or commercial)
  • Working with stained glass
  • Painting pictures or making jewellery using artist’s paint
  • Hunting
  • Target shooting
  • Fishing sinkers
  • Car body repair and paint removal
  • Car battery breakdown in the garage or yard
  • Plumbing
  • Other exposure for example, lead flashing around chimneys
  • Lead dust contaminated work cloth
  • Tin food from overseas (from lead in solder)
  • Some alternatives medicines and cosmetics
  • Lead in food and beverage containers

Who is at risk of getting lead poisoning?

  • Infants
  • Preschool children
  • Young children
  • Adults
  • Pregnant women
  • Unborn child

What are the public health risks?

Infants and children

Infants and young children are particularly at risk of developing lead poisoning when they come in contact with flaking paint or lead-contaminate dust or soil. The reason is they often put objects in their mouth such as toys or their fingers that may be contaminated with dust or soil. Paint on old cots, old toys such as rocking horses or blocks could be lead-based. Young children absorb more of the lead they take in than older children and adults.

Adults

Adults are at risk of developing lead poisoning by inhalation from activities such as restorations, renovations or cleaning older houses. Not washing lead-contaminated hands properly before eating or smoking is a risk factor. The highest level of lead in adults occurs during occupational exposure.

Unborn children

In unborn children, lead can be carried to the unborn child through the mother’s blood. When pregnant women are exposed to lead through repainting, through work exposure or through hobbies (for example lead lighting, indoor small bore rifle shooting) it may affect the baby while it is still being formed. Exposure to lead can cause premature birth or low birth as well as later problems in development.

Signs and symptoms of blood lead poisoning

The signs/symptoms of blood lead poisoning are non-specific and affects the gastrointestinal and nervous systems. Symptoms that affect the nervous systems are (i) mood changes (such as depression or irritability), (ii) memory impairments (iii) sleep disturbance (iv) headache (v) tingling and numbness in fingers and hands.

Symptoms of lead poisoning that affect the stomach and intestine can include (i) lack of appetite (ii) nausea (iii) diarrhoea (iv) constipation (v) stomach pain (vi) weight loss.

In later stages, symptoms may develop in the blood, kidneys, bones, heart and reproductive systems.

In children, if low blood lead levels are left untreated, it can affect the developing brain and may impair young children’s development and later performance at school.

High levels can cause symptoms such as vomiting, stomach pain, difficulty sleeping, constipation and lack of appetite.

Diagnosis

Lead can be diagnosed by measuring the amount of lead in the blood.

If you, family members, relatives or friend think you have been exposed to lead please contact Population Health for advice.

If you think you have developed symptoms as a result of exposure to lead please contact your GP or practice nurse.

For requests, information, enquiries and complaints on chemical poisoning, please contact Population Health.

For up-to-date information please visit the Centre for Disease Control and Prevention(external link) website.

Information for health professionals

For requests, information, enquiries and complaints on lead and lead poisoning, please contact Population Health.

For up-to-date information on lead please visit the following websites:

All occupation-related lead exposure should be dealt with by the Health and Safety unit in the workplace.

All Health and Safety units are expected to have guidelines or information in place for the management of any workplace exposure.

A Notifiable Occupational Disease System form should be filled out and sent to Health and Safety, Ministry of Business, Innovation and Employment for assessment.

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