A drone photo taken on Oct. 20, 2025 shows a view of Yellow River Estuary in Dongying, east China's Shandong Province. (Photo: Xinhua)

China's Ministry of Public Security released four typical cases of committing crimes of environmental pollution on Wednesday, involving the manufacturing and sale of cheating chips used to interfere with vehicle emissions testing and illegal disposal of hazardous waste.

The release came ahead of World Environment Day, which falls on Friday, as the ministry vowed to crack down on environmental pollution and protect ecological security and Chinese people's health.

The ministry said in a case investigated by the public security authorities in Shaoxing, East China's Zhejiang Province in November of 2024, involving suspects led by a man surnamed Shan who manufactured and sold cheating chips to interfere with vehicle emissions testing. The suspects used technical means to conceal the actual emission levels of vehicles. As a result, pollutants such as nitrogen oxides and particulate matter from vehicle emissions caused exacerbated compound pollution in the region, including smog. 

After the case came to light, the public security authorities, relying on police-civilian collaboration mechanisms, worked together with environmental protection and market regulation departments to carry out cross-regional tracing and investigation. They quickly located the chip production sites, sales networks, and end-user facilities, thereby cutting off the criminal chain.

The ministry said that in May 2025, public security authorities in Hechi, South China's Guangxi Zhuang Autonomous Region, cracked a case of environmental pollution involving the illegal disposal of hazardous waste, by arresting 10 suspects. 

The investigation found that a metallurgical chemical company and an environmental technology company, in an effort to reduce hazardous waste disposal costs, illegally transported industrial filter press sludge to Hechi for disposal. During transportation and disposal, no pollution prevention measures were taken, posing a serious threat to local environment and public health.

The remaining two cases involve the illegal discharge of excessively polluted industrial wastewater in Southwest China's Chongqing Municipality. The investigation revealed that the head of a pharmaceutical factory's wastewater station, with tacit approval from company officials, interfered with automatic monitors and secretly discharged untreated wastewater. COD levels at the discharge outlet exceeded the permitted standard by nearly 12 times.

In the case of Luzhou city, Southwest China's Sichuan Province, the illegal transfer, dumping and landfilling of industrial solid waste damaged soil structure, contaminated surface and groundwater systems, and posed a serious threat to the safety of surrounding water sources as well as the stability of the local ecosystem.

Global Times