Known as the world's factory, Dongguan is a leading production base for garments and gadgets. One-fifth of the world's smartphones are produced there, as are one-fifth of the world's sweaters.

With so many factories crammed into a region around twice the size of Hong Kong, detecting pollution sources has long been a challenge for environmental inspectors.

Drones have offered a solution.

Equipped with several high-precision gas sensors, the drone is capable of detecting eight air pollutants, such as volatile organic chemicals (VOCs), sulfur dioxide, nitrogen dioxide and PM2.5.

Hovering around 100 meters from the ground, the flying machine transmitted real-time monitoring data and geographic coordinates. Within 30 minutes, the drone produced a distribution map showing the levels of VOCs. Three red dots on the map indicated abnormal levels of the gas in the area.

Law enforcement officers then located the source of the pollution and punished three factories that had directly discharged waste gas into the air.

In addition to detecting eight types of pollutants, the drone can record information, including time, longitude and latitude, while collecting data to create an analysis report.

Source: Xinhua