Number of oil industry accidents reported in Louisiana so far in the wake of Hurricane Isaac, according to an analysis by the Louisiana Bucket Brigade: 93

Pounds of pollution released in those incidents, a conservative figure given that amounts are self-reported by polluters: 4.9 million

Minimum gallons of pollution that were released: 171,000

Pounds of sulfur dioxide -- a toxic chemical associated with respiratory problems, preterm births and premature death -- released during the disaster by the Chalmette refinery, a joint operation of Exxon Mobil and Venezuela's national oil company, located just east of New Orleans: 554,000

Pounds of other volatile chemicals released in that incident, which was reportedly caused by a hasty shutdown despite ample advance warning of the storm's approach: 10,000

Pounds of benzene, a chemical known to cause cancer, that were released: 100

Number of accidents reported at that refinery from 2005 through 2012 that involved pollution releases: 491

Total number of pounds of toxic chemicals released in those incidents: 6,881,115

Pounds of toxic chemicals including cancer-causing benzene and butadiene that the Shell Motiva refinery in Norco, La. reported releasing during Isaac after it failed to keep its flare lit and vented directly to the atmosphere: unknown

Date on which St. Charles Parish, where the Shell Motiva refinery is located, issued a mandatory evacuation order: 8/26/2012

Date on which Isaac came ashore in Louisiana: 8/28/2012

Date on which Shell shut down the refinery without explanation, after keeping it operating at reduced capacity during the storm: 8/30/2012

Number of accidents reported at the Shell Motiva refinery from 2005 through 2012 that involved accidental pollution releases: 205

Total number of pounds of toxic chemicals released in those incidents: 1,823,421

Gallons of oil spilled during Isaac from a storage tank facility owned by Texas Petroleum Investment Co. of Houston and located in the Delta National Wildlife Refuge in Plaquemines Parish, La.: 16,800

Amount that company was fined in September 2011 for violating federal spill prevention control regulations at two storage tank facilities in Louisiana, including its Plaquemines Parish operations: $134,895

Amount the company was fined in August 2011 for Clean Water Act violations at oil production facilities in Plaquemines and four other Louisiana parishes, and for spilling oil into wetlands: $163,487

Year in which the company was sentenced to two years of probation for violating the federal Clean Water Act by negligently causing a spill from its Plaquemines Parish operations: 2009

Amount it was ordered to pay in fines and other penalties for that incident: $525,000

(Click on figure to go to source. Much of the data and the map are from the Louisiana Bucket Brigade, a grassroots environmental health and justice nonprofit based in New Orleans. For a larger version of the map, which does not show all 93 incidents, click here.)