Alexander "Sandy" Messent Cairncross OBE (born 8 March 1948) is an epidemiologist at the London School of Hygiene and Tropical Medicine (LSHTM).
Most of his career has been spent in research and teaching, and about a third in developing countries implementing water, sanitation and public health programmes.
[3] Cairncross was appointed Officer of the Order of the British Empire (OBE) in the 2011 Birthday Honours for services to environmental health overseas.
[4] In January 2014, Cairncross was awarded the Edwin Chadwick Medal in recognition of his outstanding contributions to the advancement of public health.
[3] Until 2015, he served as chair of trustees to Teaching-aids at Low Cost (TALC), an international non government organization with charitable status based in Hertfordshire.