The mining disaster that killed more than 200 workers in Turkey has underscored the health and safety problems in the country's mining sector.
Experts say poor oversight from regulators, a weak health and safety culture and an uneducated and unorganized workforce have contributed to making Turkey a particularly dangerous country in which to be a miner.
Here's a Q&A that explains some of the biggest problems with mining in Turkey.
HOW COMMON ARE DEADLY MINING ACCIDENTS IN TURKEY?
According to statistics compiled by the International Labor Organization, 1,172 mining deaths were reported in Turkey in 2001-2012. That's about 100 deaths a year.
A report in March by the state-run statistics institute says 10.4 percent of all work accidents are related to mining.
HOW DOES THAT COMPARE WITH OTHER COUNTRIES?
International comparisons are hard to come by because not all countries collect and report statistics in the same way. But experts say the Turkish numbers are high compared to those reported by most other mining nations. For example, Britain, whose mining sector historically has had a high number of fatalities, only saw an average of six mining deaths annually in 2007-2012, according to safety officials. That was just 1 percent of all work-related deaths in Britain during that time.
In the U.S., deaths linked to mining fell below 100 a year in the 1990s and reached historic lows of 35 deaths in 2009 and 2012, according to the U.S. Labor Department. It says the drop is a result of legislation regulating the mining industry and advances in technology, mining methods and training.
China's mines are notoriously deadly, although safety improvements have significantly reduced the deaths in recent years. Industry reports from last year say more than 1,300 people died in mining accidents in China in 2012 and 1,973 died in 2011, according to the State Administration of Work Safety. The figures do not include missing people.
WHY ARE TURKISH MINES SO DANGEROUS?
Researchers point to a number of factors, including cultural attitudes toward workplace safety and poor oversight of working conditions and safety standards.
For one, Turkey hasn't ratified the International Labor Organization's Safety and Health in Mines Convention.
A paper published last year by researchers Yucel Demiral and Alpaslan Erturk at Dokuz Eylul University in Izmir, Turkey, said health and safety inspections in Turkish mines are divided between different authorities, and the lack of coordination among them results in ineffective supervision. Also, their paper points to the lack of education and the low level of organization among Turkish miners as a contributing factor to unsafe working conditions.
Though Turkey's ambition to join the European Union has prompted it to adopt many of the bloc's health and safety standards, in many cases EU directives have just been translated into Turkish, but not harmonized with local regulations, leading to confusion. As a result, those regulations haven't been put into practice, their paper says.
HOW CAN TURKEY IMPROVE MINING SAFETY?
Andrew Watson, operations manager at Britain's Mines Rescue Service, said that attitudes toward safety — putting safety before production — and using technology that warns of dangerous conditions are key to safe mining operations.
In British coal mines, for example, every mining machine has a monitor to measure the level of methane, an explosive gas. When the level reaches a trigger point, the power to the machines is automatically cut off. "That way you remove the ignition source," Watson said.
Stressing that he didn't know whether that type of technology was in use in the Turkish mine where the latest accident occurred, he said the frequency of large-scale accidents suggests Turkey has a problem with safety controls. "Whether it's faulty equipment or management or supervision, something has gone wrong with the controls," he said.
Perhaps illustrating Turkey's somewhat fatalistic approach to mining disasters, Prime Minister Recep Tayyip Erdogan said after a mining accident in 2010 that killed 30 miners that death was part of the "profession's fate."
WHAT MAKES MINING DANGEROUS?
Mining always has been a hazardous occupation, although health and safety standards have been improved significantly in many countries.
Coal mining can be particularly dangerous. Safely removing the coal from a mine is challenging because coal is often found between soft layers of rock that are prone to cave-ins. Also, the mining operations can result in the release of noxious or explosive gases and potentially explosive coal dust.
Operating heavy machinery in dark and cramped conditions deep underground presents additional risks.