Original sentence: Source 1 is fairly constant: minimum around 0.47 kg CO2 per kg of cement, maximum 0.54, typical value around 0.50 world-wide.This significantly increases local air pollution and has on occassions led to produce from surrounding farms being considered unfit for human consumption due to high levels of heavy metals, pcbs, dioxins, etc.g UK) averaging around 0.30
Edited sentence: Source 1 is fairly constant: minimum around 0.47 kg CO2 per kg of cement, maximum 0.54, typical value around 0.50 worldwide.This significantly increases local air pollution and has on occasions led to produce from surrounding farms being considered unfit for human consumption due to high levels of heavy metals, pcbs, dioxins, etc.UK) averaging around 0.30