Kirk is a Professor of Environmental Microbiology with over 30 years of research experience and is Lancaster University's Director of International Research. His main fields of research interest include pollutant-microbe interactions in soil; biodegradation, bioavailability and bioaccessibility of pollutants in soils, and risk assessment and bioremediation of contaminated land and, most recently, the use of microorganisms for energy generation and the application of the resulting by-products as soil amendments or alternatives to conventional fertiliser. A particular area of expertise lies in organic contaminant bioavailability in soil, and it is in this area where his reputation is best known internationally. As Director of International Engagement in the Lancaster Environment Centre and then the Assistant Dean International for the Faculty of Science and Technology, he became involved in international activities and partnerships for the University. Most of his international activities have been in Sub-Saharan Africa, where he has supported collaborations with universities and research institutes, private sector organisations and government/policy experts in Sierra Leone, Ghana, Nigeria, Cameroon, Kenya, Uganda, Malawi, Zambia, Botswana and Angola.