Poisoning a City: The Case of Flint, Michigan
Simply outrageous and horrifying:
A group of Virginia Tech researchers who sampled the water in 271 Flint homes last summer found some contained lead levels high enough to meet the EPA's definition of "toxic waste." The researchers posted their test results online, which I represent graphically below with other visuals to help understand just how high above normal Flint's lead levels really were. Lead in water is measured in terms of parts per billion (ppb). If a test comes back with lead levels higher than 15 ppb, the EPA recommends that homeowners and municipalities take steps to reduce that level, like updating pipes and putting anti-corrosive elements in the water when appropriate. But 15 ppb is a regulatory measure, not a public health one. Researchers stress that there is no 100 percent "safe" level of lead in drinking water, only acceptable levels. Even levels as low as 5 ppb can be a cause for concern, according to the group studying Flint's water.
So let's start with Flint's neighboring cities. At the city level, public health officials are most concerned with the 90th percentile level of lead exposure in homes they test -- that is, 90 percent of homes will have a lead level below this threshold, while 10 percent will register above it. Forty-five minutes away from Flint in Troy, Mich., the 90th percentile level for lead in 2013 was 1.1 parts per billion. Not too shabby at all.
In the graphics that follow, each splotch represents 1 part per billion. The splotches aren't proportionally scaled to the cups -- 1 part per billion is way too small to be visualized at this level. But all of the following graphics are scaled proportionally to each other, to give an impression of relative lead levels. In Detroit, the water supply Flint had previously been connected to, the 90th percentile reading was 2.3 parts per billion -- still highly acceptable. Here's an illustration of water at the 5 parts per billion level. This is below the borderline for EPA acceptability, but the team of researchers studying Flint's water say that levels this high can be a cause for concern, particularly for young children.
Now things get interesting. Here's a glass illustrating the 90th percentile reading among the 271 Flint homes tested by researchers last summer: At 27 parts per billion, it's five times as high as the level of concern, and nearly twice as high as the EPA's already-generous guidelines. According to the researchers who ran these tests, the health effects of lead levels this high "can include high blood pressure and other cardiovascular problems, kidney damage and memory and neurological problems." Recall, though, that 10 percent of the homes in the sample had lead levels even higher than this.
Here's the highest lead reading in that sample, from a home in the city's 8th Ward: That's more than 10 times the EPA limit. It's 30 times higher than the 5 ppb reading that can indicate unsafe lead amounts. But that 158 ppb reading is far from the worst one that turned up in Flint, unfortunately.
In the spring of 2015, city officials tested water in the home of LeeAnne Walters, a stay-at-home mother of four and a Navy wife. They got a reading of 397 ppb, an alarmingly high number. But it was even worse than that. Virginia Tech's team went to Walters' house to verify those numbers later in the year. They were concerned that the city tested water in a way that was almost guaranteed to minimize lead readings: They flushed the water for several minutes before taking a sample, which often washes away a percentage of lead contaminants. They also made residents collect water at a very low flow rate, which they knew also tended to be associated with lower readings. So the Virginia Tech researchers took 30 different readings at various flow levels.
What they found shocked them: The lowest reading they obtained was around 200 ppb, already ridiculously high. But more than half of the readings came in at more than 1,000 ppb. Some came in above 5,000 -- the level at which EPA considers the water to be "toxic waste." (original piece has the graphics, which were not copied here)I'm sure this whole catastrophe and the slow response by the GOP governor has nothing to do with the fact that Flint is 55% African American...