Industry knowledge from Wikipedia:

Agriculture is a major industry in the United States, which is a net exporter of food.

Agriculture encompasses crop and livestock production, aquaculture, fisheries and forestry for food and non-food products. 

Agriculture ranks among the most hazardous industries due to the use of chemicals and risk of injury. Farmers are at high risk for fatal and nonfatal injuries, work-related lung diseases, noise-induced hearing loss, skin diseases, chemical-related illnesses, and certain cancers associated with chemical use and prolonged sun exposure. 

In an average year, 516 workers die doing farm work in the U.S. (1992–2005).

Agriculture in the U.S. makes up approximately 75% of the country's pesticide use.

United States agricultural workers experience 10,000 cases or more of physician-diagnosed pesticide poisoning annually.

Fertilizer Production

Fish Industry

Food Processing

Grain Silos

Heat Production:  Processes using Combustion

Horticulture: Greenhouses

Livestock: Pigs and Cattle

Mushroom Farming

Orchards:  Smudge Pot Heating

Pesticides

Soybean Oil Extraction