BEIJING - China's supreme court and procuratorate jointly issued a new judicial explanation Tuesday that imposes harsher punishments on polluters.

The new legal document, which will take effect on Wednesday, confronts difficulties in investigating environmental pollution cases and in convicting polluters, according to a statement issued by the two judicial departments.

With more precise criteria for convictions and sentencing, the document is expected to facilitate the work of judges and tighten punishments for polluters, it said.

The document lists 14 types of activity that will be considered "crimes of impairing the protection of the environment and resources."

For instance, discharging, dumping or treating radioactive waste or waste containing infectious disease pathogens or toxic substances into sources of drinking water and nature reserves will be seen as a crime.

Activities that result in pollution that forces more than 5,000 people to be evacuated or poisons more than 30 people will also be defined as crimes.

Those who pollute near hospitals, schools or large residential areas will be considered serious offenders.

According to the country's Criminal Law, those convicted of such crimes will face a maximum prison term of seven years and be subjected to fines.

Before the judicial explanation, the law had not clearly defined what activities could result in criminal charges, said Hu Yunteng, a senior researcher with the supreme court.

"Now it is clearer and easier for the judge to decide," he said.

The new document also lowers benchmarks for convicting and sentencing, he said.

According to the judicial explanation, a person can be convicted if he or she is responsible for pollution that seriously injures a person. Previously, the pollution would have to result in death in order to convict a person of this crime.

Under the current law, the sentence can only be increased if three or more people die from the pollution. Only one death will be required after the judicial explanation takes effect.

"The new document is stricter, since people can be convicted once they commit the crimes specified, even without proven consequences," Hu said.

More than 10 million hectares of farmland are polluted and heavy metals and pesticide residue that people ingest through food have greatly threatened public health, said Qian Guanlin, a senior national political advisor.

"Environmental pollution is a major reason for the high incidence of cancer in China," said Qian, vice director of the population, resources and environmental committee under the National Committee of the Chinese People's Political Consultative Conference (CPPCC).

Also on Tuesday, the Ministry of Public Security announced that police have detained 118 suspects involved in environmental pollution cases since January.

Police said most of the cases involved mines or petrochemical factories, including a number of large factories that pay significant taxes and thus have a great deal of support from local governments.

The new judicial explanation also targets organizations that are involved in polluting, said Sun Jungong, a supreme court spokesman.

Organizations can cause much worse environmental consequences than individuals if they do not abide by the law, Sun said.

The new document states that executives and other people directly responsible for an organization's polluting activities will be treated as individual offenders and the organization will be fined.

At a study session held with members of the Political Bureau of the Communist Party of China (CPC) Central Committee in late May, President Xi Jinping pledged that China will not sacrifice the environment for temporary economic growth.

Last week, the State Council, or China's cabinet, adopted a set of measures to counter air pollution, including restraining energy-consuming and polluting industries, transforming the country's energy structure and enhancing the transparency of environment-related government information.