IF YOU have to pick a single city to illustrate the precipitous economic decline of America’s rust belt, look no further than Flint, Michigan.

Immediately after Flint changed its provider, the city’s residents began complaining about the colour and smell of the water coming out of their taps.

In September 2015 Mona Hanna-Attisha, a paediatrician, said she had found that the level of lead in the blood of infants from Flint had doubled since the city started getting its water from the river.

A new study by Daniel Grossman of West Virginia University and David Slusky of the University of Kansas shows that in the year following the city’s change of water supplier, the number of births per woman aged 15-49 fell by 12% compared with the average over the previous eight years, while fetal deaths increased.

Moreover, the authors warn that the latter figure may be an underestimate, since their data account for neither abortions nor miscarriages that occur in the first 20 weeks of gestation, and do not cover all hospitals.