The Mission has higher rates of asthma and lower incomes than most San Francisco neighborhoods. And proximity to freeways and busy streets is as common as access to parks and green space, according to the Department of Public Health’s Program on Health, Equity & Sustainability.

The program analyzes by neighborhood several factors: access to healthy foods, obesity, and physical activity; housing; transportation; open space and parks; air quality and noise; and segregation. Findings appear in maps and tables that also rank the incidence of several chronic illnesses for 26 neighborhoods.

Crunching the numbers against the maps reveals some alarming patterns. Using the Inner Richmond as a control neighborhood that is also fairly diverse and dense and not financially off the charts, comparisons are telling.

In the “Proportion of Households Living within 500 feet of Busy Roadways” table, the Mission scores 81% versus 59% for the Inner Richmond. Busy roadways are defined by the California Air Resources Board as freeways and urban roadways with between 10,000 and 100,000 vehicles per day, depending on the distance (i.e., 10,000 vehicles within about 200 feet or 100,000 within 500 feet). The board recommends not siting schools, parks or playgrounds, daycare centers, nursing homes, hospitals, and residential communities within these distances. This leaves just 19% of the Mission for safe usage!

Pehaps not coincidentally, the incidence per 100,000 residents of adult and pediatric asthma, adult diabetes, chronic obstructive pulmonary disease, and adult congestive heart failure is approximately twice as high in the Mission as in the Richmond for all four: 411 versus 206, 530 versus 172, 573 versus 214, and 1409 versus 856, respectively.

Disease isn’t the only killer that likes the sunny Mission. The rate of pedestrian injury collisions per 100,000 residents is 153, compared with 91 in the Inner Richmond. Only the Financial District (1382) and South of Market (413) have higher proportions. The citywide average is 104.

These statistics and more form the basis for the DPH’s Healthy Development Measurement Tool, which is described as “an evidence-based practice to consider public health objectives in land use planning.” Such statistics may warm a scientist’s heart, but they also make most people’s eyes glaze over. What do they mean in practical terms? Why does the Mission suffer such harm compared with a similar neighborhood across town?

Unfortunately, the studies don’t answer these questions, but some theories seem plausible. The Mission is located close to major downtown and SOMA employment centers at one end and to two major freeways at the other. So even though a smaller percentage of actual residents drive alone to work, more commuters from outlying neighborhoods and towns down the Peninsula drive through the Mission.

The numbers support this argument. The percentage of households in the Mission with at least one vehicle is 62%, compared with 79% in the Inner Richmond. The percentage of Mission commuters who drive alone is 62%, while 42% take transit, and 7% bicycle. Comparable numbers for the Richmond are 79%, 34%, and 2% (these add up to more than 100% because commuters may cite more than one mode of travel; walking was close to equal in the 2%-3% range). While more Richmondites may be driving, their number of vehicle crashes in the period from 2001 to 2005 was 854 versus 2463 for the Mission. Bicycle collisions for the same period numbered 40 out west versus 240 here at home.

The fact that much of the traffic harming such a disproportionate number of Mission residents may come from elsewhere adds insult to injury. And matters could soon get worse. SamTrans is considering fare hikes and service cuts in December that would make it harder for Peninsula commuters to take transit, upping the potential for more cars on those freeways and arteries from the south. Proposals on the table would reduce service on several lines that serve San Francisco.

In addition to traffic, the Mission is closer to industrial areas and power plants that increase pollution throughout the southeastern part of the City. The weather may also be a factor, as the Mission lacks the Richmond’s constant winds off the ocean to help blow pollutants away.

While planners can do little about the weather, however, this DPH study alerts them to land use factors that harm a neighborhood that is poor (per capita income in 1999 dollars of $22,879, compared with $34,219 for the Richmond) and dense (23% of households living in overcrowded conditions versus 9%). The most overcrowded neighborhood is Chinatown (36%), and the poorest is Bayview ($14,482). Their opposites are the Marina (1%) and Pacific Heights ($86,583). Citywide averages are 11% and $34,556.

Numbers freaks can find further information at www.sfphes.org or www.thehdmt.org.

Fran Taylor can be reached at duck.taylor@yahoo.com.