How has our relationship with milk changed pollution in the last 200 year

It has increased pollution a lot as now milk is processed in factories that emit poisonous gases.

The factories are mainly responsible for producing pollution.

Explanation:

The changing technology has caused a severe impact on the environment. The increase in advancement of technology is a cause for the development of factories.

The factories used methods which produces pollution. The use of harmful gases in milk production factories is a major cause of pollution. Thus our relationship with milk changed pollution in the last 200 year.