Lead poisoning
Too much exposure to lead can cause lead poisoning and associated health problems. It can take months or years to develop lead poisoning if you are exposed to a small amount. A lot of lead exposure can quickly lead to more serious lead poisoning.
Symptoms of lead poisoning
The early stages of lead poisoning are not specific. They can affect your nervous system and cause symptoms such as:
- mood changes such as depression or irritability
- memory issues
- sleep issues
- headaches
- tingling and numbness in fingers and hands.
Lead can also affect your stomach and intestinal symptoms. This can cause:
- lack of appetite
- nausea
- runny poos (diarrhoea)
- dry poos or difficulty pooing (constipation)
- stomach pains
- weight loss
- irritability or impaired mood.
In later stages, lead poisoning can affect your blood, kidneys, bones, heart or reproductive systems.
In extreme cases lead poisoning can cause convulsions, coma or death.
Symptoms in tamariki
Low amounts of lead exposure does not cause obvious symptoms. But if untreated, it can affect the developing brain of tamariki and their development.
High levels of lead exposure can cause symptoms such as:
- vomiting
- stomach pains
- difficulty sleeping
- constipation
- loss of appetite
- reduced IQ
- poor behaviour.
If untreated, very high blood lead levels can cause more serious problems, and lead to brain damage or even death.
How you get exposed to lead
Lead is a naturally occurring metal that may be found in the home or work environment. Lead gets into your body through food, water and air. You either eat or drink it, or breathe in dust particles. Once in the body, lead circulates in the blood and can be stored in the bones and organs.
Almost all lead inhaled is absorbed. Children absorb 50% of ingested lead after a meal and 100% on an empty stomach. Some people will develop health problems or lead poisoning if they are exposed to too much lead over time.
Most lead exposure comes from lead-based paint on houses built before about 1970, especially those before 1945.
The old paint might still be in place, painted over or flaking off. When you remove old paint or it flakes off it can get into dust or soil.
Lead-based paint (internal link)
Lead can get into drinking water if lead pipes or tap fittings are breaking down. The amount of lead in the water depends on:
- how corrosive the water is
- what the pipes or fittings are made from
- the amount of time the water is in contact with the pipe or fittings.
If you work in jobs such as auto repair, mining, pipe fitting, battery manufacturing, painting or construction you may be exposed to lead. This means you can also bring it home on the clothes you work in.
Infants and preschool tamariki often put objects or their hands in their mouth. Because of this they may put lead-contaminated dust, soil or objects in their mouth.
Paint on old cots or old toys, such as rocking horses or blocks, could also be lead-based. Tamariki will chew on lead-painted items because lead paint tastes sweet.
Young tamariki absorb more lead than older tamariki and adults.
Unborn pēpi
Lead can be carried to your pēpi during pregnancy through your blood. If you are exposed to lead during pregnancy it may affect your pēpi while it is still forming.
Exposure to lead can cause premature birth or low birth weight as well as later problems with development.
Alternative medicines are often classed as dietary supplements. They may not comply with the same safety standards as conventional medicine. Asian alternative medicines and products that may contain lead and other heavy metals include:
- Ayurvedic medicines
- Chinese traditional medicines
- skin-lightening products
- some ceremonial powders (sindoor)
- traditional cosmetics such as eyeliner
- some food additives.
It is recommended that people who buy alternative medicine products:
- only purchase medicines where the contents are clearly listed and known to be safe
- do not buy Ayurvedic and other alternative medicines over the internet
- consult their healthcare provider or pharmacist before taking an alternative medicine
- seek immediate medical attention if they become unwell while taking an alternative medicine
- be careful about products brought into Aotearoa New Zealand as 'personal imports' by travellers.
Indoor shooting is sometimes associated with raised blood lead levels.
It is particularly important not to carry lead home on your body and clothing if you will be in contact with pregnant women or young children.
Appendices 5 and 6 in The Environmental Case Management of Lead-Exposed Persons have advice on minimising lead exposure for indoor shooters and shooting club ranges.
The Environmental Case Management of Lead-Exposed Persons — Health New Zealand (external link)
Some amateur fishers, shooters and divers like to make their own weights and bullets. If you do this you need to be very careful about your lead exposure as you may release lead into the environment, often in small enclosed spaces, such as your shed or garage.
Hobby activities like stained glass panel making and car repair are also potentially risky.
Diagnosing lead poisoning
Symptoms of lead poisoning are similar to many other health conditions. If you or your tamariki have any of these symptoms and think you may have had lead exposure, visit a healthcare provider or call Healthline on 0800 611 116
Your healthcare provider can do a blood test to measure the amount of lead in your blood. This will be from a finger prick or from a vein.
There is no safe blood level of lead. Depending on the results of the test, your healthcare provider will recommend future testing to check your levels. If your levels are very high they might suggest treatment.
If your blood lead level is equal to or greater than 0.24 µmol/l your result will also be notified to public health.
The role of public health
Public health staff:
- receive complaints about lead exposure and other hazardous substances in non-workplace settings
- provide advice to individuals with lead poisoning on how to reduce their exposure, and also protect their whānau
- investigate potential sources of lead poisoning in non-workplace settings.
If medical officers of health reasonably believe that lead poisoning has occurred at a workplace, they must advise WorkSafe New Zealand for follow-up.
Treatment for lead poisoning
For low-level exposure
The first step of treating lead poisoning is to remove the source of the lead.
For people with relatively low lead levels, avoiding exposure to lead might be enough to reduce blood lead levels.
If you cannot remove lead from your environment, you might be able to reduce the chances of it causing issues. For example, if there is lead in your house it might be better to paint over lead paint rather than remove it.
Your local public health unit can give you information on ways to find lead and reduce exposure.
For high-level exposure
For more severe cases of lead poisoning, your healthcare provider might recommend chelation therapy.
This medication is usually taken by mouth. The medicine binds with the lead so that your body can wee it out.
Some adults with very high levels of lead, or tamariki who cannot tolerate the medicine may be treated with chelation medication given by injection.
Preventing lead poisoning
There are a few ways you can protect yourself and your whānau from exposure to lead.
- Avoid known sources of lead.
- Eat iron and calcium rich food such as meat, beans, legumes, milk, cheese or yogurt. These foods help absorb lead.
- Wash your hands before you eat.
- Wash dummies and toys frequently, especially those used outside.
- Wet-wipe floors, ledges, window sills and other flat surfaces at least once a week.
- Take care renovating or repainting old homes. Assume the paint is lead-based if the house was built or painted before 1970. Avoid sanding.
- Avoid drinking water that contains lead. Run the tap for a few seconds before using water. Run taps each morning for 30 seconds to clear water that has been sitting in pipes overnight.
If you collect rainwater for drinking, check your roof and guttering for materials that may contain metals that may have lead — for example, lead flashing, lead-headed nails, and lead paint. Replace these if you find them.