Summary
Aotearoa New Zealand (NZ) is in the throes of an unprecedented asbestos exposure incident from asbestos-contaminated children’s play sand. Children who have been exposed to asbestos have an increased dose-dependent risk of mesothelioma (cancer of the lining of the lung) later in life. Further investigation of the level of this asbestos exposure is required to give a better indication of the magnitude of risk. This assessment can inform decisions on how best to mitigate risk for exposed children (eg, monitoring or tracking via a register).
NZ legislation recognises asbestos-associated health risks, controls import of asbestos-containing products, and provides for redress if health is affected. However, asbestos testing of products for importation into NZ is not covered by any NZ legislation. We recommend that products at risk of contamination are tested at the border to minimise asbestos-associated health risks.
Asbestos is carcinogenic
The World Health Organisation’s International Association for Research on Cancer categorises asbestos as Carcinogen Group1 (sufficient evidence for human carcinogenicity).1 It causes several cancers, including mesothelioma, a rare cancer of the lungs’ lining.2 Asbestos can also cause asbestosis due to inflammation leading to scar tissue in the lungs. This requires prolonged exposure to asbestos fibres.
Asbestos comprises several forms. Blue asbestos (crocidolite) poses the greatest mesothelioma risk because its fibres are sharp and can be small enough (<10 µm, see Giuseppe et al.3) to be respired deep into the lungs where they penetrate cells and can cause cancer.4,5 The lag period between exposure and mesothelioma is usually around four decades, but higher exposure levels can lead to shorter lag periods.6
Asbestos-contaminated Children’s play sand
The chance finding (November 2025) during routine analysis in Australia that children’s play sand is contaminated with asbestos was reported to the NZ authorities on 5 November.7 This alert led to frenzied activity to assess and mitigate the health risks to exposed children. Some schools were closed while testing occurred. Asbestos-containing sand was disposed of and the school environments deep cleaned to prevent further exposure. Multiple agencies have provided guidance on recall of products, cleanups of potentially contaminated areas, and potential health effects, including MBIE (and Product Safety NZ), Ministry of Education, Worksafe, and Health New Zealand.
When parents became aware, they were concerned about the health risks to their children playing with asbestos-contaminated play sand at school and home. Many parents sought expert advice, which led to numerous samples being analysed and cleaning protocols advised. This was the first incident of this type in NZ, so no approaches were in place to mitigate the risks.
Health risks following exposure to asbestos-contaminated play sand
The level of risk is determined by the type of asbestos present and the magnitude of exposure. Analyses of play sand found tremolite – a brown asbestos, which presents a lower cancer risk than blue asbestos. Tremolite occurs in two forms, fibrous and crystalline. Fibrous presents a greater cancer risk than crystalline because of its sharp fibrous nature. The more dangerous fibrous form has been identified in play sand.
Because there have been no assessments of exposure levels, we can only conclude that inhalation exposure to asbestos-contaminated play sand presents a mesothelioma risk, but we cannot assess the level of risk. It has been known since the 1960s that asbestos exposure via the lungs in rats leads to mesothelioma8 and decades later that the magnitude and duration of inhalation exposure to asbestos in humans determines mesothelioma risk.9 In the current situation, the magnitude and duration of exposure are not known, hence the need for a full risk assessment.
Further investigation of the level of exposure in children playing with asbestos-contaminated play sand (perhaps in collaboration with the Australian authorities who are tackling the same problem) might indicate the magnitude of exposure (eg, concentration of asbestos fibres in air in the play area), so giving a better indication of the magnitude of risk. Indeed, not all the coloured sand products analysed have been found to contain asbestos. This shows that further investigation will allow us to better understand the risk of exposure to asbestos in children’s play sand.
Child versus adult cancer risk
People exposed in childhood might have a greater risk of developing mesothelioma than those exposed as adults.10 For lung cancer following second hand smoke exposure, people exposed prior to age 25-years had greater cancer risk than those exposed later.11 This fits the hypothesis that children are more susceptible to carcinogens because they are growing and developing, so their cells divide more frequently than adult cells, and we know that dividing cells are more susceptible to carcinogens.
Can we mitigate mesothelioma risk in exposed children?
Once carcinogenesis is initiated by asbestos the process cannot be reversed. However, early detection can improve outcomes. Unfortunately, mesothelioma diagnosis is often late because it relies on patients presenting with symptoms and ‘obvious’ symptoms usually occur late in the disease’s development.12 Following a comprehensive assessment of exposure, health authorities should explore possible options for mitigating risk in exposed children, if necessary. If the exposure assessment suggests that there is a risk of asbestos-related disease, then actions considered could include monitoring or follow-up of exposed children in adulthood to ensure early diagnosis and improved prognosis. Mesothelioma treatment has a low success rate (e.g., 28% chemotherapy response rate).12
Asbestos Exposure Reporting
The monitoring of children may be assisted by the reinstatement of the voluntary Asbestos Exposure Register (AER), which stopped taking new registrations in late 2023.13 A reinstated AER, however, should be wider in scope than its former incarnation, which was primarily focused on asbestos exposure at work. Australia’s National Asbestos Exposure Register (NEAR) appears to be wider in scope.14
Addressing asbestos cancer risk by legislation
The Imports and Exports (Asbestos-containing Products) Prohibition Order 2016 states, ‘The importation of an asbestos-containing product is prohibited unless the importation is authorised by a permit’. However, there is no requirement to routinely test imports for asbestos contamination. Further, the Health and Safety at Work (Asbestos) Regulations 2016 recognise workplace asbestos exposure-associated health risks by regulating its handling and disposal.
The Consumer Guarantees Act 1993 (CGA) states that products must be both safe and fit for purpose. Clearly, asbestos-containing play sand is not, but the CGA does not specifically require testing to ensure safety. Under the CGA the consumer can recover reasonably foreseeable loss and damage caused by unsafe products (excluding medical costs, loss of earnings and so on, as these are covered by the Accident Compensation Act 2001). So, these Acts are useful to respond to a problem, but not to prevent a problem arising. Testing of products for importation into NZ for asbestos contamination is not covered by any NZ legislation.
Clearly, there is a need for asbestos testing in products at risk of contamination at the border to reduce the risk of them entering NZ and adversely affecting New Zealanders’ health. Legislation to require testing, at the importer’s expense, would be required. The Ministry of Business, Innovation and Employment would be the most appropriate regulator to fulfil this task.
Revision notice
An earlier version of this article recommended ongoing monitoring of exposed children. Following post-publication feedback, this recommendation has been updated (12 Dec 2025) to clarify that any such action should occur only after a full exposure assessment has been completed, to indicate the magnitude of risk, and guide subsequent decisions about mitigation.
An archived version of the original article is available on request from the Public Health Communication Centre.
What this Briefing adds
- Measuring the magnitude of exposure to asbestos fibres is the key to quantifying cancer risk in exposed people.
- In the case of children exposed to asbestos-contaminated play sand, airborne asbestos fibres in play areas were not measured, making the magnitude of the cancer risk to the children in later life impossible to determine. Modelling studies could be used to assess the magnitude of airborne asbestos produced from disturbed children’s play sand, which would indicate the magnitude of exposure and thus risk.
- Current NZ legislation places the requirement of ensuring asbestos-free products on importers and suppliers, who, as the play sand incident demonstrates, are not fulfilling their legal responsibilities.
Implications for policy and practice
- Further work (potentially in collaboration with Australian authorities) to estimate airborne asbestos levels in the air environment around play sand play areas is necessary to estimate the magnitude of children’s exposure and future cancer risk.
- There is a need for legislation requiring asbestos testing of potentially contaminated products for importation into NZ at the border, undertaken or overseen by a regulator, such as MBIE.
Author details
Prof Ian Shaw, Professor of Toxicology, School of Physical & Chemical Sciences, Te Whare Wānanga o Waitaha | University of Canterbury
Prof Alex Sims, Professor of Commercial Law, Department of Commercial Law, Waipapa Taumata Rau | University of Auckland
