Air monitoring by the EPA shows that along parts of Gulf Coast, the air may be unhealthy for people “who are unusually sensitive to air pollution.”

The numbers reflected by the real-time air monitoring maps tend to fluctuate, but as of this morning, about half of the 29 sampling sites showed “moderate” levels of particulate matter pollution—that’s down from Wednesday afternoon, when most of the air sampling sites were “moderate” rather than “good.”

The Louisiana Bucket Brigade, an environmental health and justice organization, said this week that while the EPA’s monitoring program does “represent progress,” it “falls short in many ways.”

“The EPA continues to use a limited number of monitoring sites to extrapolate to a broad region,” the Bucket Brigade said in an analysis of the agency’s air monitoring [PDF]. “If the EPA does not have the data then they should simply state that fact.”

When asked, the EPA told me that "at this point we have been unable to determine if any of this [particle pollution found] is related to the spill, although it is possible." It added that "to date, EPA has not found any pollutants at levels expected to cause long-term harm."

The National Oceanic and Atmospheric Administration also released air sampling findings on Wednesday, which it said were "consistent" with the EPA's findings. The agency said most of the pollution levels were comparable to those on a bad day in an urban area such as Los Angeles, but nearer the Deepwater Horizon site, the air "was polluted with organics from the spill," and levels of benzene and toluene--some of the most concerning constituents of crude oil--were "well above maximum concentrations measured recently over the Los Angeles urban area."

It’s also worth mentioning that since we last relayed statistics on oil spill-related illnesses, both BP and states have released new numbers:

The Louisiana Department of Health and Hospitals reported this week that 290 illnesses were believed to be related to chemical exposure from the oil spill—216 of those from workers and 74 from the general public.

According to the Alabama Department of Public Health, at least 105 people were treated for health complaints believed to be related to the oil spill, the Mobile Press-Register reported on Wednesday. The Alabama numbers are only since May 14, however—almost a month into the spill. Alabama doesn’t break these statistics down into workers versus the general public.

BP’s latest count—which spans from April 22 to July 12—recorded 647 illnesses and 955 injuries from Gulf cleanup workers.

The illness and injury numbers for workers on the spill may see a decline if the surface cleanup efforts continue to wind down. The company announced this week that it has  reduced the number of skimmers working in the Gulf by more than a quarter, now that the cap on the well is holding in most of the oil. (The decision to cut down on the number of boats skimming oil comes just as OSHA rolls out its new and improved safety training, a few weeks later than promised.)

Update: This post has been updated with the EPA's response.

Follow @mariancw