Complex sentence: Pollutants such as sulphurous oxides (SO x), nitrous oxides (NO x), and particulate matter (PM) are produced from this combustion; the World Health Organisation estimates that 7 million premature deaths are caused each year by air pollution.
Split into simpler sentences: Pollutants such as sulphurous oxides (SO x), nitrous oxides (NO x), and particulate matter (PM) are produced from this combustion. The World Health Organisation estimates that 7 million premature deaths are caused each year by air pollution.