The occupational lead absorption rate dropped in 2020
The occupational lead absorption notification rate has decreased from 3.0 per 100,000 (122 out of a total of 206 lead notifications) in 2019 to 1.4 per 100,000 (59 out of 110 lead notifications) in 2020. The nationwide lockdown from COVID-19 may have contributed to the low rate in 2020.
Figure 1: Occupational lead (15+ years) and adult lead absorption notification rate, by year (Crude rate per 100,000)
- In 2007, direct laboratory notification was introduced, the 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.
- In 2020, New Zealand enters nationwide lockdown due to COVID-19.
- 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 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.
Over 90% of the occupational lead notifications were males
In 2014–20, nearly all of the occupational lead notifications were males (421 out of 447 occupational lead notifications, 94%)(Table 1).
Table 1: Median blood lead level, interquartile range and number of occupational lead notifications by working-age group (15+ years) and sex, 2014–20
Nearly 80% of the occupational notifications had blood lead levels less than 0.96µmol/L in 2020
The blood lead level groupings are based on the Ministry of Health guidelines, which provide recommendations for the management of elevated lead levels according to the level of blood lead (Ministry of Health 2021).
In 2020, of the 59 occupational notifications, 54.2% (32 notifications) with blood lead levels 0.48–0.71µmol/L, 25.4% (15) with 0.72–0.95 µmol/L, 18.6%(11) with 0.96–2.16 µmol/L, and 1.7% (1) with 2.17+ µmol/L.
In 2014–20, the majority (67%) of the occupational lead notifications had blood lead levels below 0.96µmol/L (Figure 2).
Figure 2: Number of occupational lead absorption notifications, by working age-group (15+ years) and blood lead level, 2014–20
Pacific workers had the highest occupational lead absorption notification rate in 2014–20
In 2014–20, Pacific workers had the highest occupational lead absorption notification rate (2.5 per 100,000) (Table 2).
Table 2: Occupational lead absorption by prioritised ethnic group, 2014–20
Painters remain the most notified group with occupational lead since 2014
In 2020, painters remained the most notified group with occupational lead absorption, accounting for approximately 41% of work-related notifications. This has remained the same since 2014. Other high ranking groups include foundry, builder, radiator, metal and glazier workers (Table 3).
Table 3: Number of occupational lead absorption notifications, 2014–20
Wairarapa DHB and Regional Public Health had the highest reported rates of occupational lead absorption
In 2014–20, people living in the Wairarapa DHB had the highest reported rate of occupational lead absorption (7.8 per 100,000; 21 notifications) compared to other DHBs (Table 4). Similarly, Regional Public Health reported the highest rate (3.3 per 100,000; 97 notifications) of occupational lead absorption. These are most likely due to increased use of the HSDIRT in these areas rather than an increased exposure to lead. On the other hand, there were no lead cases reported for Northland, Lakes, Tairāwhiti and Nelson Marlborough DHBs.
Table 3:Occupational lead absorption notification rate and number of notifications, by DHB and PHU, 2014–20
Information about the data
This data source, only includes cases that were notified and will be underestimating the total burden of disease and injury caused by lead exposures. Also, a case will not be included in the analysis if the GP is unaware of the tool and does not use it to notify cases or the laboratory does not directly notify the blood lead result to EpiSurv.
Lead absorption is challenging to detect based on symptoms alone as many cases are asymptomatic and will therefore not be seen by a doctor and/or have a blood lead test. In some instances a blood lead test will occur because of awareness of the person’s occupation.
1.BPAC. 2021. Lead absorption notification levels have reduced. Occupational medicine: Public Health URL: https://bpac.org.nz/2021/lead.aspx (Accessed 10 August 2021)
2.Ministry of Health. 2021. The environmental Case Management of Lead-exposed Persons. URL: https://www.health.govt.nz/publication/environmental-case-management-lead-exposed-persons (Accessed 10 August 2021)