Neng Nana
Two former directors of the Hong Kong Observatory (HKO) have issued a stark warning, urging the Labour Department to urgently revise its Heat Stress at Work Warning system. Their call comes in the wake of record-breaking temperatures that triggered only the lowest alert level, exposing outdoor workers to potentially dangerous conditions. Lee Boon-ying and Shun Chi-ming, both respected figures in Hong Kong’s meteorological community, penned a joint op-ed in Ming Pao on Thursday, asserting that the current system employs an incorrect heat stress reference, leading to a critical delay in issuing appropriate warnings.
The controversy ignited earlier this week when Hong Kong endured its hottest day in 143 years on Sunday, with temperatures soaring to 36.9 degrees Celsius at the HKO headquarters in Tsim Sha Tsui and a blistering 38.9 degrees Celsius in Sheung Shui. Despite these extreme readings, the Labour Department’s Heat Stress at Work Warning remained at the amber level, the lowest of its three-tier system. This seemingly insufficient response prompted widespread criticism and concern for the well-being of individuals laboring outdoors.
A System Based on Flawed Metrics
Lee and Shun contend that the Labour Department’s Heat Stress at Work Warning system is fundamentally flawed due to its reliance on the HKO’s Heat Index (HI). While the HI is designed to assess the combined health impacts of heat stress by considering temperature, humidity, wind speed, and solar radiation, the former directors argue it is unsuitable for evaluating the risks faced by outdoor workers.
“The HI is a standard of reference for the general public, who might likely be indoors in an air-conditioned environment,” Lee and Shun explained in their op-ed. “It is not meant for people working outdoors.” They further elaborated that the system is calibrated to issue an amber warning when the HI reaches 30. However, they pointed to a joint study by the HKO and the Chinese University of Hong Kong, which indicates that hospitalizations begin to rise significantly when the HI reaches this very threshold. This suggests that the current trigger point for even the lowest alert is already at a level where health risks are becoming apparent.
The Critical Lag in Protection
Adding to their concerns, Lee and Shun highlighted the inherent delay in the warning issuance process. “Moreover, issuing and delivering warnings takes time, leading to a lag that prevents outdoor workers from taking timely precautions,” they stated. This delay means that by the time a warning is disseminated and understood, workers may have already been exposed to dangerously high heat levels for a significant period. The cumulative effect of such exposure, especially over extended workdays, can lead to severe heat-related illnesses, including heatstroke, exhaustion, and potentially fatal outcomes.
“Due to this insufficient protection, the practice of issuing warnings fails to reassure people,” the former directors emphasized, underscoring the inadequacy of the current system in providing genuine safety and peace of mind for vulnerable workers.
The Urgent Need for Scientific Re-evaluation
In their appeal to the Labour Department, Lee and Shun expressed their “sincere hope” that the department will heed public sentiment, community groups, and expert advice. They strongly advocate for a scientifically sound adjustment to the warning system, proposing the adoption of the “wet-bulb globe temperature (WBGT)” as a more appropriate metric.
The WBGT, an index introduced by the HKO in 2008, is specifically designed to measure heat stress experienced by individuals engaged in physical activity in outdoor environments. It takes into account air temperature, humidity, wind speed, and solar radiation, providing a more comprehensive and accurate reflection of the thermal load on the human body under direct sun exposure and strenuous conditions. By shifting to WBGT, the Labour Department could implement a warning system that is more attuned to the real-world challenges faced by outdoor workers.
A Pattern of Insufficient Action?
The controversy surrounding the heat stress warning system is not entirely new. Just days before the record-breaking temperatures, Lam Chiu-ying, another former HKO director, publicly criticized the system, labeling it “decorative.” His remarks echoed the sentiment that the current framework lacks the robustness to genuinely protect workers.
The Labour Department, faced with mounting pressure and public outcry, announced on Tuesday that it would indeed revamp the system. However, the timing of this announcement, coming after the extreme heat event and the subsequent criticism, raises questions about the proactive measures taken to ensure worker safety. The introduction of the three-tier Heat Stress at Work Warning system itself in May 2023 was intended to offer enhanced protection, with employers advised to implement measures such as longer breaks for outdoor workers or those in non-air-conditioned environments. Yet, the effectiveness of these advisory measures is severely hampered if the warning signals themselves are not triggered appropriately.
Broader Implications of Extreme Heat
The concerns raised by Lee and Shun extend beyond the immediate inadequacy of the warning system. They pointed to the escalating threat of extreme heat in the context of global warming. “Extreme heat is the biggest ‘weather killer’ in Hong Kong, claiming more lives than severe weather events such as typhoons, rainstorms, and thunderstorms,” their op-ed stated. This assertion is supported by epidemiological data that consistently shows a correlation between high temperatures and increased mortality rates, particularly among vulnerable populations, including outdoor laborers, the elderly, and those with pre-existing health conditions.
With global warming trends projecting an increase in the frequency and intensity of heatwaves, the risk to Hong Kong’s workforce is set to grow. This underscores the critical importance of having a responsive and scientifically sound heat stress warning system. A failure to adapt could lead to a significant rise in heat-related illnesses and fatalities, placing an undue burden on the healthcare system and impacting the productivity and well-being of the city’s essential outdoor workers.
A Call for Proactive Governance
The joint appeal by Lee Boon-ying and Shun Chi-ming serves as a crucial reminder of the need for continuous evaluation and improvement of public safety measures, especially in the face of evolving environmental challenges. Their call for the Labour Department to “listen to the public, community groups, and experts, and to act on good advice by making scientifically sound adjustments” is a plea for a more evidence-based and citizen-centric approach to policymaking.
The implications of this debate are far-reaching. It highlights the disconnect that can sometimes exist between scientific recommendations and practical implementation of public safety policies. It also emphasizes the responsibility of government departments to engage with expert advice and community feedback to ensure that protective measures are not merely symbolic but genuinely effective in safeguarding citizens.
The coming weeks will be crucial in determining whether the Labour Department will translate its commitment to revamping the system into tangible, science-backed changes that offer meaningful protection to outdoor workers against the growing threat of extreme heat in Hong Kong. The health and safety of a significant segment of the workforce depend on it.
Sagoh
Azzam Bilal Chamdy
