We humans are subject to hyperbolic discounting, not taking full account of long distant future costs for current pleasures, sometimes those running the public health system really do know more than us, there are externalities associated with these behaviours (late night drunks, passive smoking and the visual pollution of someone 300 lbs overweight perhaps).

FORBES: Alcohol, Obesity and Smoking Do Not Cost Health Care Systems Money

It is not a compelling visual argument that air pollution is linked to autism.

FORBES: 5 Caveats About The Autism And Air Pollution Study

But villagers say the dairy will be too close to their homes and the school, and objections have been raised about noise, the smell, flies, pollution, increased traffic, the size of the development and its visual impact.

BBC: Powys 'mega dairy' plan public inquiry comes to an end