Materials

Any industry which consumes large amounts of raw materials , will obviously produce a lot of products and bi-products and waste.

The amount of product is a function of the demand-supply cycle.

The amount of bi-product is directly proportional to the amount of product. If there is no demand for the bi-product then it also becomes waste that must either be stored (awaiting a demand) or "dumped".

The waste must be stored responsibly until there is a "market" for it ... which in many/most cases that means "in perpetuity" !

Energy

All manufacturing processes consume energy.

If combustion is the source of the energy, then there must be end-products...emissions ( gases..."particulates"...steam... toxics...etc.)

Natural gas (methane)  is purported to be one of the cleanest fuels; it releases carbon dioxide (a greenhouse gas) and water.

Coal is one of the "dirtiest" fuels; it releases many harmful substances when burned.

Electricity by itself releases only heat but its production may also be a source of emissions.

Smoke

All combustion produces heat and "smoke". Smoke refers to any/all of the products of combustion...both visible and invisible.

The heat produced causes the gases to expand and rise. Chimneys/stacks are constructed to carry the smoke from the immediate area and to send it passively by the wind to "who-knows-where"!

Modern or up-to-date technology attempts to clean the smoke by

• preventing the production of the smoke at its source
• constructing "scrubbers" or "filters" or "bag-houses" (vacuum cleaners)  in the stacks... to capture or "clean" the smoke

Dust

• is any fine particulate
• it can originate from many sources:  crushing, loading, dumping, grinding, scaling, smoke, roadways...
• can cause adverse adverse respiratory effects regardless of its chemical composition