BEIJING - Several key indices for pollution and energy consumption dropped in the first half of the year, a senior official said Wednesday.

Drops in the indices for Chemical Oxygen Demand, a main index for water quality, as well as emissions of sulfur dioxide, ammonia nitrogen and nitrogen oxide, either met or exceeded set targets, said Zhang Ping, minister in charge of the National Development and Reform Commission, while delivering a report at the bi-monthly session of the Standing Committee of the National People's Congress.

The index for energy intensity, or units of energy use per unit of gross domestic product, also dropped in the first six months, he said.