PL07 GLOBAL SPREAD OF ASBESTOS-RELATED DISEASES: STILL SERIOUSLY UNDER-RECOGNIZED
Authors: Takahashi Ken , Brislane Kim 
Published: July 2024

Introduction

The position of the United Nations (UN) Agencies on asbestos, led by the World Health Organization (WHO) and the International Labour Organization (ILO), is clear and unwavering. They assert that asbestos ranks among the most important occupational carcinogens and advocate for the elimination of asbestos-related diseases (ARDs) through the cessation of asbestos use. Their recent focus has centred on chrysotile asbestos [1], the single fibre type traded globally and applied industrially since around the 1990s. This implicit endorsement of a worldwide asbestos ban has seen implementation in over 60 countries, although the majority are economically developed. As a result, there has been a noteworthy reduction in global raw asbestos consumption to approximately 1.2 million metric tonnes per year [2]. Despite this progress, the manufacturing and consumption of asbestos-cement construction materials persist at substantial per capita levels, especially in developing Asian countries. Notably, the recent momentum in countries adopting asbestos bans appears to be waning.

Materials and Methods

This presentation consolidates existing knowledge and accumulated experience regarding the current global spread of ARDs, explores the implications of their under-recognition, and re-evaluates strategies for effective policy-making.

Results

1. Asbestos-Related Diseases (ARDs)

Malignant mesothelioma develops predominantly on the pleura, and to a lesser extent, on the peritoneum, with an attributable fraction of 90% or more. As such mesothelioma is widely accepted as the “indicator disease” related to asbestos. It is one of the most fatal human cancers with limited treatment options. Although relatively rare, it is rapidly increasing and diagnosis proves challenging in developing countries. Asbestos-related lung cancer (ARLC) has an attributable fraction of about 10% but is anticipated to surpass mesothelioma by 6-times in terms of cases. The Helsinki Criteria for Diagnosis and Attribution [3] serve as the standard reference for diagnosing ARLC, but its diagnosis is also challenging in developing countries. An essential characteristic of ARDs is their long latency period following asbestos exposure, reaching 30-40 years or longer, particularly with mesothelioma. Regarding causality, the International Agency for Research on Cancer (IARC), through extensive literature reviews, consistently concludes that there is sufficient evidence to establish that asbestos causes human cancer [4]. Various national and international authorities align in designating asbestos as a human carcinogen. Prominent international scientific bodies like the International Commission on Occupational Health (ICOH) [5] and the Collegium Ramazzini [6] have long advocated for a global asbestos ban recognizing the insurmountable human costs associated with its use.

2. Global Burden of ARDs

Mesothelioma deaths are reported to the WHO by various countries, but the quality and availability of data are roughly proportional to a country’s national income level [7]. This is due to the challenge of diagnosing mesothelioma, coupled with a general lack of socio-medical infrastructure as well as awareness, particularly in less developed countries. Statistical data on ARLC deaths are scarce, and even among developed countries, comparisons are challenging. The Global Burden of Disease (GBD) Study for 2019 [8] estimates that annual deaths caused by occupational exposure to asbestos total 239,000, of which 236,000 are all cancers, 199,000 are lung cancer (ARLC), and 27,000 are mesothelioma. Asia is of particular concern, as the estimated numbers of mesothelioma deaths of Asia show a faster increasing trend than other regions. This pattern is expected because a number of Asian developing countries, including densely populated ones, have consistently reported high levels of asbestos consumption. While GBD estimates are considered authoritative, there is considerable uncertainty regarding ARDs, especially in less developed countries.

3. Ecological Relationships – Evidence for Policy

The continued substantial use of asbestos in many developing countries underscores the need for innovative approaches alongside conventional methods that emphasise accumulation and dissemination of evidence on causality.

Ecological relationships, drawn from country-level data, provide supporting evidence for national policies. In our 2022 study [9] covering 198 countries, we found that the historical burden of mesothelioma deaths and their identification often prompted countries to ban asbestos. A straightforward 2 by 2 analysis revealed that most countries banning asbestos had identified mesothelioma, while twice as many non-banning countries did not identify mesothelioma. Similarly, countries not identifying mesothelioma were less likely to ban asbestos. The estimated mortality rate of mesothelioma was highest in the subgroup where asbestos was banned and mesothelioma was identified, with a decreasing gradient towards the subgroup where asbestos was not banned, and mesothelioma was not identified.

The National Asbestos Profile (NAP), an annexed template to the WHO/ILO National Program for the Elimination of Asbestos-Related Disease, allows countries to measure progress towards eliminating ARDs and discontinuing asbestos use. Our 2021 global survey [10] found that only 14 countries formulated the NAP, including three high-income countries that had already banned asbestos. Encouragingly, eight lower middle-income countries, still using asbestos, developed the NAP. Despite being nderutilized, this tool holds significant potential for countries to learn from other countries and assess their own status.

Training workshops, often coordinated with the WHO, the ILO and the United Nations Environmental Programme, have raised awareness and facilitated technology development in asbestos-using countries. The University of Occupational and Environmental Health, Japan (UOEH) and the Asbestos and Dust Diseases Research Institute of Australia (ADDRI) have been enduring leaders. In the post-COVID-19 era, the challenge for asbestos-using countries is to rekindle stakeholder interest and regain momentum towards positive transitions. The ADDRI has additionally created the e-Toolkit for Eliminating ARDs in Developing Countries accessible at https://adri.org.au/whocc/etoolkit-2021/. This resource offers a rich collection of educational text, along with hyperlinks to valuable external sources and originally developed educational videoclips. To ensure maximum accessibility, these videos are now captioned with the 6 UN languages (Arabic, Chinese, English, French, Russian and Spanish).

Conclusions

Despite ongoing calls from UN Organizations for countries to eliminate ARDs and discontinue asbestos use, the recent pace of asbestos bans seems to be decelerating. The majority of the global burden of ARDs remains concealed, with estimations presenting significant concerns, particularly in developing Asian countries. Various countermeasures designed to facilitate the implementation of asbestos bans by countries have yet to be fully deployed. Drawing on acquired knowledge and experience, the presenters suggest prioritizing the identification of mesothelioma cases (i.e., the indicator disease) and the formulation of NAP in training curricula that target countries continuing to use asbestos. Efforts must be intensified to bolster global awareness and action to address this ongoing public health threat.