Editing Petroleum (section)

===Chemicals===
{{Further|Petroleum product| Petrochemical}}
[[File:Alkene General Formula V.1.svg|thumb|General structure of an [[alkene]]]]
Many [[pharmaceutical]]s are derived from petroleum, albeit via multistep processes.{{Citation needed|date=February 2024}} Modern medicine depends on petroleum as a source of building blocks, [[reagent]]s, and [[solvent]]s.<ref>{{cite journal |pmid=21778473 |date=2011 |last1=Hess |first1=J. |last2=Bednarz |first2=D. |last3=Bae |first3=J. |last4=Pierce |first4=J. |title=Petroleum and health care: Evaluating and managing health care's vulnerability to petroleum supply shifts |journal=American Journal of Public Health |volume=101 |issue=9 |pages=1568–1579 |doi=10.2105/AJPH.2011.300233 |pmc=3154246 }}</ref> Similarly, virtually all pesticides - [[insecticide]]s, herbicides, etc. - are derived from petroleum.  Pesticides have profoundly affected life expectancies by controlling disease vectors and by increasing yields of crops.  Like pharmaceuticals, pesticides are in essence petrochemicals. Almost all plastics and synthetic polymers are derived from petroleum, which is the source of monomers. [[Alkenes]] (olefins) are one important class of these precursor molecules.