Editing Bitumen (section)

== Health and safety ==
[[File:Asfaltna baza Ivanovec.1.jpg|thumb|An asphalt mixing plant for hot aggregate]]

People can be exposed to bitumen in the workplace by breathing in fumes or skin absorption. The [[National Institute for Occupational Safety and Health]] (NIOSH) has set a [[recommended exposure limit]] of 5{{nbs}}mg/m<sup>3</sup> over a 15-minute period.<ref>{{cite web|title = CDC – NIOSH Pocket Guide to Chemical Hazards – Asphalt fumes|url = https://www.cdc.gov/niosh/npg/npgd0042.html|website = cdc.gov|access-date = 27 November 2015}}</ref>

Bitumen is a largely inert material that must be heated or diluted to a point where it becomes workable for the production of materials for paving, roofing, and other applications. In examining the potential health hazards associated with bitumen, the [[International Agency for Research on Cancer]] (IARC) determined that it is the application parameters, predominantly temperature, that affect occupational exposure and the potential bioavailable [[carcinogenic]] hazard/risk of the bitumen emissions.<ref name="IARC">{{cite book |last=IARC |url=http://monographs.iarc.fr/ENG/Monographs/vol103/ |title=Bitumens and Bitumen Emissions, and Some N- and S-Heterocyclic Polycyclic Aromatic Hydrocarbons |volume=103 |location=Lyon, France |publisher=[[International Agency for Research on Cancer]] |year=2013 |isbn=978-92-832-1326-0 }}</ref> In particular, temperatures greater than 199{{nbs}}°C (390{{nbs}}°F), were shown to produce a greater exposure risk than when bitumen was heated to lower temperatures, such as those typically used in asphalt pavement mix production and placement.<ref>{{cite journal|last1=Cavallari|first1=J. M.|last2=Zwack|first2=L. M.|last3=Lange|first3=C. R.|last4=Herrick|first4=R. F.|last5=Mcclean|first5=M. D.|title=Temperature-Dependent Emission Concentrations of Polycyclic Aromatic Hydrocarbons in Paving and Built-Up Roofing Asphalts|journal=Annals of Occupational Hygiene|volume=56|issue=2|year=2012|pages=148–160|issn=0003-4878|doi=10.1093/annhyg/mer107|pmid=22267131|doi-access=free}}</ref> IARC has classified paving asphalt fumes as a [[List of IARC Group 2B carcinogens|Class 2B]] possible carcinogen, indicating inadequate evidence of carcinogenicity in humans.<ref name="IARC" />

In 2020, scientists reported that bitumen currently is a significant and largely overlooked source of [[air pollution]] in urban areas, especially during hot and sunny periods.<ref>{{cite news |title=Asphalt adds to air pollution, especially on hot, sunny days |url=https://phys.org/news/2020-09-asphalt-air-pollution-hot-sunny.html |access-date=11 October 2020 |work=phys.org |language=en}}</ref><ref>{{cite journal |last1=Khare |first1=Peeyush |last2=Machesky |first2=Jo |last3=Soto |first3=Ricardo |last4=He |first4=Megan |last5=Presto |first5=Albert A. |last6=Gentner |first6=Drew R. |title=Asphalt-related emissions are a major missing nontraditional source of secondary organic aerosol precursors |journal=Science Advances |date=1 September 2020 |volume=6 |issue=36 |pages=eabb9785 |doi=10.1126/sciadv.abb9785 |pmid=32917599 |pmc=7467703 |bibcode=2020SciA....6.9785K |url=|language=en |issn=2375-2548}}</ref>

A bitumen-like substance found in the Himalayas and known as ''[[shilajit]]'' is sometimes used as an [[Ayurveda]] medicine, but is not in fact a tar, resin or bitumen.<ref>{{Cite book|last=Nadkarni |first=Dr. K. M. |editor-last=Nadkarni |editor-first=A. K. |title=Indian Materia Medica|volume=2|pages=23–32|publisher=Popular Prakashan |date= 1994 |isbn=81-7154-143-7}}</ref>