The manufacturing hub Dongguan city's police recorded 893 cases of sudden unexplained nocturnal death syndrome from January 2001 to October last year.
The number of deaths has tripled with a total of 231 such cases recorded from January 1990 to December 1999, the South China Morning Post reported.
The sharp increase came to light after researchers at Zhongshan School of Medicine based in Guangzhou released their analysis of police records of deaths in Dongguan over the past two decades.
The men who died usually experienced an abrupt difficulty in breathing before death, the school's studies into the syndrome said, but the cause remained unclear.
The syndrome is mostly noted in the Southeast Asian countries including Thailand, Vietnam and the Philippines.
It first drew the attention of mainland medical scholars when an increasing number of migrant workers in Dongguan were reported to have died suddenly in their sleep in the 1990s.
The recent analysis of cases in Dongguan reported a similar pattern to international studies, suggesting that young male manual labourers were at greatest risk.
It said that long working hours as well as poor sanitation and ventilation in their living and working spaces might have put the workers at higher risk.
Workers' rights groups in Guangdong have long been concerned about the sudden deaths of migrant workers, which they believed were caused by overwork, according to Zeng Feiyang, the director of the Guangdong Panyu Migrant Worker Centre in Guangzhou.
"It is especially hard to help the victims get compensation since the concept of overwork has not been recognised by Chinese law," Zeng said.
The analysis also found people aged 20 to 40, usually the breadwinners under heavy pressure, were at highest risk.
More than 80 per cent of the 328 people who died during 2001 and 2006, for instance, were aged between 21 and 40.
More than nine out of every 10 victims were male, according to the report.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
