The answer is increased environmental pollution.
Step-by-step explanation:
During the Industrial Revolution, the population did decrease as more people moved to more urban locations to work in factories and industries. Transportation was improved with the development of things such as canals, waterways, and railroads. The middle class emerged during the Industrial Revolution, and it all started with the increase of retail shops that grew from 300 to about 2,600 from 1875 to 1890. In none of this is increased environmental pollution mentioned.