The correct option is: "Londoners developed breathing problems due to the smog. - Coal mines polluted the surrounding environment."
Coal was the main source of energy for the first Industrial Revolution, fueled the steam engine and was crucial in the steel industry. Until the industrial revolution, the most used energy came from wood and charcoal. Its consumption was producing a huge deforestation.
Although the operation of the mines (iron beams to support the galleries, methods of ventilation, methods to extract the water, use of trolleys on rails) was greatly improved, in order to increase the productivity, the work in them became something very dangerous and very painful.
The Industrial Revolution in the mid-eighteenth century caused many people to move from the villages to London, shooting the smog during the winters. Its high point came in the winter of 1952. London was paralyzed for five days by smog.
The west faced
similar social barriers as the South.
<span>Chinese immigrants had come to the West in search for jobs in association
with the Transcontinental Railroad. Due to their differences in manners, customs,
and wage expectations, they were met with discriminatory laws and riots. </span>
