Prof. Andrew C Johnson

My position at UKCEH has allowed me to develop considerable expertise in the fate and risks of chemicals in the environment. 

This has included: the fate of pesticides in soils and groundwater; the fate of endocrine disrupting chemicals together with pharmaceuticals in rivers; and the fate of nanoparticles in soils and rivers; the fate of microplastics in wastewater and drinking water.  Typically my approach is to start by researching the consumption and discharge of the chemical to the environment, assessing its fate, its distribution, its exposure levels and comparing these to toxicity thresholds.  This requires an expertise in critical reviews, laboratory and field studies together with modelling. 

My interests have expanded to evaluate lessons learned from previous environmental issues and advocate the use of weight of evidence approach to risks from chemicals to the natural environment.  Currently I am trying to evaluate if and where chemicals actually harm wildlife populations in the UK https://www.ceh.ac.uk/our-science/projects/chempop-does-discharge-chemicals-environment-harm-wildlife-populations . This takes me to the position of the necessity for wildlife, physical and chemical monitoring to be integrated and supported long-term to assess human impacts on the environment.

First employed at Wallingford (originally known as Institute of Hydrology) in 1992.  In 2000 I was promoted to: Principal Scientific Officer, CEH Wallingford (now UKCEH)

The focus of studies has been in assessing risks,and more importantly the impacts, of chemicals and substances in the environment.

With the NERC funded study on chemicals and populations ‘ChemPop’ this has allowed me to review how chemical exposure has influenced biodiversity in freshwater, terrestrial and marine environments. Recent project management roles include: project managing UKWIR studies on microplastics in the water infrastructure; NERC funded study on risks from chemicals in China; Defra studies on nanosilver in rivers, sediments and sludges; project managing Defra study on developing a new chemicals strategy for the water environment; project manager of NERC/EA initiative on assessing the chemical contamination of wild fish in our rivers using long-term monitoring; project managing Defra study on the progestogens in sewage effluent and the risks they pose to the aquatic environment; work package leader in the EU project NanoFATE responsible for overseeing the modelling of nanoparticles in the soil and water environment; deputy work package leader in the EU project PHARMAS responsible for overseeing the modelling of selected drugs in the soil and water environment and for performing environmental risk assessments for these compounds; and co-PI on Defra study on the influence of effluent exposure on fish genetics.

Since 2004 I have been a member of the UK/Japan collaboration on endocrine disrupters supported by Defra. This has involved several trips to laboratories around Japan to communicate the UK experience and liaise with Japanese scientists. I was invited to give evidence to a session of the House of Commons Science & Technology Committee in February 2013 on pharmaceuticals in water and in April 2019 to the Environmental Audit Committee on chemicals in everyday life. I advise as a hydrological expert for the UK Ministry of Justice Tribunal Service. I was invited to brief the Government Chief Scientist and Civil Servants of the Cabinet Office on the risks posed by endocrine disruption in May 2014. From 2014 to 2021 I was a member of the Hazardous Substances Advisory Committee which is the pre-eminent committee considering matters of chemical pollution in the UK.  I helped form, as Co-Chair, the Science Advisory Group of the Environment Agency Monitoring review in March 2018. Since 2023 I am a member of the Water Industry Substances of Emerging Concern Advisory Group.

As of July 2023 the Web of Science reports 154 papers with over 7,800 citations and an H-index of 51 for my scientific papers. 25 papers have now passed over 100 citations each.

2012 onwards: Visiting Professor at Brunel University, UK I have a long-term collaboration with the group at Brunel University led by Prof. John Sumpter working on endocrine disruption in British Rivers.

2008: Visiting Professor at Kyoto University, Japan In 2008 I worked in the Research Centre of Environmental Quality Management to assist their research in endocrine disrupters and pharmaceuticals in rivers.