My PhD focussed on spatial interpolation of climate data. I learned a lot during my, mostly statistical, PhD, but wanted to do something more applied. I realised there was a gap in the field of climate change impacts on human health. Some studies existed on vector borne diseases, but for water- and foodborne diseases not much more existed than some studies on cholera and reviews highlighting the need for quantitative studies. I envisaged a map showing the climate change impacts on waterborne diseases and set out to develop it. Now, a few years down the line, in addition to having become a mom to two daughters, I also mother the GloWPa (Global Waterborne Pathogen) model. We currently have a working model for Cryptosporidium and rotavirus emissions to surface water worldwide as well as concentrations in rivers. The simulated concentrations compared reasonably well to observations. The model can be used in scenario analysis to get an understanding of impacts of plausible future climate change, population growth, urbanisation, sanitation, waste water treatment, livestock production and management on waterborne pathogen emissions and concentrations worldwide. Moreover, management scenarios can be developed. We are also exploring opportunities to use the model in microbial risk assessment and other applications. In addition, at more local spatial scale levels, similar loads, concentrations, health risk are incorporated and we are therefore also doing sampling, modelling and scenario analysis in case study areas around the world.  I am interested in any modelling projects in the field of water and health. The work we do is interdisciplinary and therefore we rely on close contact with microbiologists, environmental technologists, hydrologists, sociologists and the like to ensure our work contributes to the state-of-the-art in those fields and provides ample opportunities to help reach the sustainable development goals. Opportunities far exceed the map that I first imagined!

A nice overview of our work is available here (in Dutch) and here (in English).


Mapping and Implementing Knowledge to Practice (K2P) Utilizing the Global Water Pathogen Project (GWPP)

I am as PI responsible for the mapping part of this project funded by the Bill and Melinda Gates Foundation project. The mapping will help decision makers to identify hotspot regions with high pathogen concentrations in surface water and compare plausible management interventions. Details about the project can be found here.

Waterborne pathogen concentrations in rivers and consequent burden of disease in Mexico City

We follow the flow from sanitation system through water to the population in Mexico City. We model these flows and use them in Quantitative Microbiological Risk Assessment. We validate the model flows using data gathered previously in Mexico City.

The GloWPa model

The GloWPa model currently estimates human and livestock Cryptosporidium and Rotavirus emissions to surface water. It is constantly further developed. Details about the model can be found here.

Quantifying the impact of flooding on E. coli concentrations in the surface waters of Kabul river in Pakistan and Betna river in Bangladesh

We seize the opportunity that rivers that flood every year provide. We measured E. coli concentrations in the rivers biweekly or monthly when there was no flooding or daily when there was a flood to study the relationship between concentrations and climate variables. We then model the hydrology and E. coli concentrations in the rivers and perform scenario analysis to study how concentrations change if floods occur more frequently, as is expected in the future. In these regions of Pakistan and Bangladesh the incidence of diarrhoeal diseases is already very large and increases in E. coli concentrations likely also mean increased pathogen concentrations and risk of disease. Climate change could strongly impact the health of the population in these regions.

The Global Water Pathogen Project (GWPP)

The GWPP mission is to be a knowledge resource and hub on water pathogens which will guide the goals for sanitation and achieving safe water around the world using the power of new information technology and tools. The knowledge hub is a developing platform to support global exposure assessments, risk assessments, and enable evaluation of sanitation technologies for achieving health-based targets. The current GWP network of scientists and students are developing an open access online resource for sharing and retrieving databases, quantitative information, tools and educational materials on pathogens associated with excreta and wastewater. We contribute a chapter to the GWPP in the case study part of the project on GloWPa and scenario analysis.


Veg-i-Trade was funded by the seventh Framework programme for research of the European Commission. The project sought to assess the impact of anticipated climate change and globalisation on the safety issues concerning fresh produce and derived food products. Our role in Veg-i-Trade was, as the leader of Work Package 9, to provide climate scenario data for the other modelling groups. Moreover, we developed a regression model that estimates microbial contamination risk of leafy greens, taking into account climate and management variables.