Health effects of hazardous substances

This section provides information that helps us to monitor injuries and diseases from hazardous substances exposure.

These data came from several different data sources likely to collectively capture hazardous substances injuries of different severity. These include lead absorption and hazardous substances notifications, hospital discharges, deaths, hazardous substances incidents, and National Poisons Centre calls.

Lead absorption notifications have increased since 2017 for adults

There were 204 notifications of lead absorption in 2019.  For adults, the notification rate of lead absorption has increased by 100% from 2017, while the notification rate for children (0 to 14 years) has remained relatively constant (Figure 1).

Figure 1: Lead absorption notification rate, by year 

  • In 2007, direct laboratory notification was introduced, the non-occupational notifiable blood lead level was lowered from 0.72 to 0.48µmol/l and enhanced occupational screening was introduced in the Auckland region. 
  • In 2013, the Hazardous Substances Disease and Injury Reporting Tool (HSDIRT) was rolled out to all health districts. Repeat blood lead level tests taken within a year of the original test has been excluded from this data unless further investigation has resulted.

Notifications peaked in 2009, with around 50 lead absorption cases associated with repainting the Auckland Harbour Bridge. This was drawn to the attention of the then Department of Labour (now Worksafe NZ) who revised their Guidelines for the Medical Surveillance of Lead Workers in 2011.  These guidelines state that employers must ensure that medical surveillance is provided to all workers involved in lead work.

Highest occupational lead absorption notification rate among Pacific people

In 2019, Pacific people had the highest notification rate – 10.8 per 100,000 (35 notifications), followed by European/Other with 3.1 per 100,000 (93 notifications).

Pacific people also had the highest occupational lead absorption notification rate (3.9 per 100,000) (Table 1).

Table 1: Occupational lead exposure vs non-occupational lead exposure, by ethnic group  (prioritised), 2014–19

Painters remain the most notified occupational group with lead absorption

In 2019, there were 120 occupational lead absorption notifications (59% of all lead notifications), compared to an average of 52 notifications per year from 2014 to 2018. Of the 2019 notifications, 49 were painters, who are the most common occupational group identified since 2014 (Table 2).

Table 2: Number of occupational lead absorption notifications, 2014–19

Gunshot wound was one of the most common identified non-occupational source of lead exposure in 2019

In 2019, there were 84 lead absorption notifications with a non-occupational or unknown source of exposure. Of the 84 notifications, gunshot wound ranked as one of the most common sources of non-occupational/unknown lead exposure with 11 notifications (Table 3). The marked increase of gunshot wound in 2019 was due to the Christchurch mosque attack.

Since 2014, frequent sources of exposure were lead-based paint, indoor rifle range and bullet/sinker manufacture.

Table 3: Number of non-occupational or unknown lead absorption notifications, 2014–19

Children are at higher risk from exposures to hazardous substances

There were 76 hazardous substance notifications in 2019 involving adults (15 years and over, 1.9 per 100,000), and 22 involving children (0 to 14 years, 2.3 per 100,000).

In 2019, there was no significant difference in hazardous substance notifications for males and females.

Across all age groups, the 00–04 year age group had the highest rate of notifications (6.2 per 100,000;19 notifications).

In 2019, essential oils such as from a reed or other diffuser and fragrance oil were the most common substance ingested unintentionally by children under five years old (4 out of 19 notifications), followed by insecticide spray  (3 notifications), and rodenticides (3 notifications). Two of the incidents involved storage of chemicals in an inappropriate container.


In 2019, there were 463 unintentional hazardous substances-related hospitalisations, and the number of hospitalisations has decreased since 2006 (563 hospitalisations).

Males continued to have higher unintentional hazardous substances related hospitalisation rates than females (Figure 2). 

Figure 2: Unintentional hospitalisations related to hazardous substances, by sex and year  (age-standardised rate per 100,000)

From 2006 to 2019, there was a marked difference in the crude rates in hazardous substances-related hospitalisation for children in the 00–04 years age group.  Children under five years of age have the highest hazardous substances-related hospitalisation rates every year, although the rate has decreased from 2006 to 2019 (Figure 3). These results are similar to those previously found [1,2].

Figure 3:Unintentional hospitalisations related to hazardous substances, by age group, 2006 –2019  (crude rate per 100,000)

Children under five years were more than six times as likely as any other age group to be hospitalised from hazardous substances related injuries caused from ‘solvents, hydrocarbons and corrosive substances’ (eg, household bleach, glue, turpentine, diffuser oil). (Figure 4)

The second highest rate of hospitalisations were injuries from ‘burns’ including fireworks, gas explosions and petrol, affecting people in all age groups, particularly people in the 15–24 year age group (3.9 per 100,000; 509 hospitalisations). These types of injuries represent 51% of all unintentional exposures.

Figure 4: Unintentional hospitalisations related to hazardous substances, by age group and substance category, 2010–2019 (crude rate per 100,000)

Forty-nine people died in 2015 from hazardous substances exposure

In 2015, there were 49 hazardous substances-related deaths registered in New Zealand. This represents a 57 percent decrease in the number of hazardous substances deaths since 2006 (88 deaths).

Between 2006 and 2015, the male age-standardised mortality rates from a hazardous substance were higher than the rates for females (Figure 5). 

Figure 5:  Age-standardised rate (ASR) per 100,000 population of hazardous substances-related deaths, 2006-2015

Toxic effects of carbon monoxide caused 430 deaths between 2006 and 2015. Death from carbon monoxide exposure was most common in the 45-64 age group (170 deaths) and 25-44 (158 deaths) year age group. 


Fire and Emergency New Zealand attends around 1,200 hazardous substances incidents every year

From 2009 to 2016, Fire and Emergency New Zealand attended 9,918 hazardous substances incidents (Table 4). This is an average of about 1,239 incidents every year. The highest number of incidents (1,436) was reported in 2010 followed by 1,354 incidents in 2015.

There was a drop in the number of incidents in 2011 and 2012 due to industrial action.

Table 4: Number of hazardous substances incidents for each alarm level, 2009-2016

Total 1152 1436 1000 1112 1322 1256 1354 1286 9918
Alarm level Year Total
2009 2010 2011 2012 2013 2014 2015 2016
1 1142 1413 988 1093 1302 1234 1321 1265 9758
2 10 22 11 18 19 17 30 18 145
3   1 1 1 1 5 2   11
4             1 3 4
Source: Fire and Emergency New Zealand

The National Poisons Centre (NPC) received 4,297 calls concerning hazardous substances in five months of 2016. Over 50 percent were related to children under five years (Table 2).

Household products were the most common exposure across all age groups (2,805 calls) (Table 5).

Table 5: Number of hazardous substances-related calls to the National Poisons Centre, by age group and substance classification, 2016

Information about the data

These data exclude poisonings from medicines, drugs, food, alcohol, and carbon monoxide where the source was not from the combustion of gas from a cylinder.

Most hazardous substances injuries are considered acute (short-term, intense exposure) rather than chronic (prolonged low intensity exposure) events. Chronic harm from hazardous substances is hard to measure because it is often difficult to determine what caused the harm. This means that data on chronic harm is hard to find and likely to underestimate the number of people affected.

For more information about the data, see the pdficon small Annual Hazardous Substances Injury Report 201 (Dec 2017) (pdf, 1.1 MB).

For more information about our hazardous substances surveillance, go to the hazardous substances surveillance webpage


1. McGuigan MA. 1999. Common Culprits in Childhood Poisoning: Epidemiology, Treatment and Parental Advice for Prevention. Pediatric Drugs 1: 313-4.

2. Yates KM. 2003. Accidental poisoning in New Zealand. Emergency Medicine 15(3): 244-9.

3. ESR. 2013. Notifiable and other diseases in New Zealand: Annual Report 2012. Porirua: Institute of Environmental Science and Research Limited. Available online:


Downloads Useful links Back to Top