title: Oil and gas wells--potential polluters of the environment?
mesh_terms: D004777:Environment; D004787:Environmental Pollution / Q000517:prevention & control; D005740:Gases; D010578:Petroleum; D014876:Water Pollution / Q000517:prevention & control*; D014877:Water Pollution, Chemical / Q000517:prevention & control
chemical_list: D005740:Gases; D010578:Petroleum