HARRISBURG — Compounds associated with neurological problems or other serious health effects are on a list of chemicals being used to drill natural gas wells in Pennsylvania.

State environmental officials say they plan to post the list online this week. It is believed to be the first complete catalog of natural gas drilling chemicals used in Pennsylvania, where the rapidly growing industry is pursuing the rich Marcellus Shale reserve.

Officials say they assembled the list using information drilling companies are required to provide. The chemicals are used in a process called hydraulic fracturing.

Environmental advocates worry the chemicals are poisoning underground drinking water sources. Industry officials say the chemicals pose no threat because they are handled safely.