Martijn van Houten - Earth Hero

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Martijn van Houten (1972) studied environmental chemistry at IJsselland University of Applied Sciences (now Saxion). He started his career at Witteveen+Bos engineering consultants and then worked for the municipalities of Hengelo and Deventer, before returning to Witteveen+Bos to put the soil department in a societal context. He loves innovation and is co-founder of the Expertise Centre PFAS and the BodemBreed Forum. 'I work more from personal drive than for money or recognition.' 

If environmental chemist Martijn van Houten had to choose between experiments with molecules or societal challenges, he would probably choose the latter. That attitude resulted in the Expertise Centre PFAS and in BodemBreed Forum. 'I grew up in the Veluwe. As a child, I won a competition and was given a nature book from forester Jonker. I loved it so much that I wanted to become a forester too. Later, as an adolescent in the 1980s, I was concerned about environmental problems like acid rain and Chernobyl. With my affinity for exact sciences, environmental chemistry was the obvious choice. It wasn't chemistry in itself that excited me. For me, it was about looking at things in a new way and getting people to think about them.' After graduating, Martijn van Houten immediately got a job at Witteveen+Bos. Lekkerkerk had brought soil pollution out of the subterranean darkness; locations like the Volgermeer polder were causing problems for government authorities. 'This whole field was in its infancy and pioneering appealed to me.' 

Can't, mustn't, won't

In 2000, however, he moved to the government, interested in the other side of the table, the client and processes involved in the project, residents, policy makers and project developers. He worked in Hengelo and later in Deventer. Exciting experiences, he says, but after four years there were certain issues that made him change course again. 'I probably wasn't a typical civil servant. I looked for bold collaborators with whom I could innovate. But I regularly came up against "can't, mustn't, won't". The final straw came when a project I had worked on for ages was eventually cancelled. I didn't want to experience that again, so I went back to Witteveen+Bos.' 
There he was given an interesting challenge: try to broaden the soil task to include the substrate, with themes like groundwater storage, organic matter content and climate. 'Over the past 15 years, we have shaped that, partly inspired by remediation of complex contaminations like the Volgermeer polder, partly by sustainable land use in the Netherlands and Europe, partly outside Europe. Brilliant fun, mixing the soil-technical side and societal ambitions. Based on an understanding of the soil system, we can give direction to what a municipality or water board wants. You take a multidisciplinary approach, while on the project side, besides the soil officer, there are people from archaeology, water and spatial planning.' 

Unwelcome message

In 2012, Van Houten became interested in PFAS: Per- and PolyFluorAlkyl Substances. These substances have been used for fifty years in fire extinguishing foam, non-stick pans, pesticides and water-repellent textiles, but there were very few agreements about them in the Netherlands. They do not biodegrade, and some proved so harmful to people and the planet that the UN Stockholm Convention (2009) banned them and declared that they must be phased out. 'Our government was saying that we were done with remediation, but I thought: really? We never looked at those PFAS!' It was an unwelcome message. The government did not want any new soil problems and was unwilling to get involved. 'But it wasn't something new. We just needed to resolve it! Because we were a commercial firm, people accused us of trying to give ourselves work. Unfairly. My motivation was that I couldn't explain to my children that I'd worked on something for decades and half of it was forgotten.' 'Together with bureau TTE, we set up the Expertise Centre PFAS. Later Arcadis joined too. This is an open platform where we develop and share knowledge. Anyone can use it and it's free.' 


It took a while before the initiative resonated in society. 'We drank countless cups of coffee all over the country and were regularly on the point of quitting. Until people in Dordrecht and surroundings became concerned about DuPont, later Chemours, which was emitting a PFAS into the air and discharging into the Merwede. People became aware that we had been using substances which may have been licensed but which were being phased out worldwide as being dangerous. How was that possible? Worldwide, we have 50 million substances. The European watchdog ECHA has drawn up a list of 150,000 substances that we need to be concerned about. The PFAS group includes more than 4,500 substances, some of which are on that list.1 Regulation is an extremely time-consuming process, taking 15 to 25 years of research per substance. Reducing that to 2.5 years must be feasible. With faster calculation technology but also with collaboration, such as in the Expertise Centre. We play on four chessboards. Firstly, we aim to improve communication between science and practice. Two: enshrining in policy. On the third board, we have problem owners like municipalities, water boards and industry. On the fourth board, there are the problem solvers, like contractors and start-ups. We connect those four boards.' After Dordrecht, the penny dropped. 'The former Ministry of Infrastructure and the Environment saw the need for a PFAS approach, and in 2016 we had got several parties to the stage where they were willing to contribute to the development of a “Guide” which could help problem owners answer their questions. What substance is it, what is the toxicity, how does it behave in soil and water? What are the risks, what standards do we set for them? How much is in the soil, where? How does the government regulate? And finally, the legal question: who is liable? For three years, we took soil samples all over the Netherlands, did research, wrote protocols and shared them with everyone. In the middle of 2018, we had a Guide. With lectures and courses about it, I must have informed 2000 people.' 

Three drops

In July 2019, the Ministry of Infrastructure and Water Management adopted a PFAS standard - with disastrous consequences. Van Houten: 'With good intentions and in line with the strict European standard, they chose an approach based on the precautionary principle. Defendable in principle, unwise in its elaboration. The limit value they set for PFAS was the one which commercial laboratories could measure: 0.1 microgram per kilo. But because the labs had no equipment which could measure less than that - compare that 0.1 with three drops of water in an Olympic swimming pool - all the results were 0.1 or higher. All earthmoving work, all building projects were stopped. A step-by-step standardisation with a higher start value would have been better. On 1 October 2019, the standard was relaxed, and recently again.' But even so, we are not there yet, according to Van Houten. 'For a building permit, we analyse a soil or groundwater sample for 30 to 40 substances and assess the potential risks. But every day we use many more substances which could pose a risk when (re)using soil and dredging spoil. RIVM currently identifies 1400 Substances of Very High Concern. Only some of these are included in those analyses. A possible solution might lie in the direction of non-target screening: not looking at individual substances but at effects. Is your soil sample an endocrine-disrupting or carcinogenic substance? What substance causes that? Another advantage is that you can trace combination toxicity. It is still an ideal but in the water world, people have taken it much further. Other solutions are also welcome.'

Is it also about effects on animals and plants?

'I worry about that, yes. The Environment and Planning Act looks at human toxicity but ignores ecological chains. I hope that we can find a solution to that.' 

Responsible for the system

Clearing contamination is one thing, preventing it is another. Is anything happening in that respect?

'Not enough to create a circular Netherlands. If the ambition is to reuse everything, products must not contain any undesired substances because they remain in the cycle. I am currently finishing a report about the prevention strategy for emerging contaminants, which says that, also in Europe, research into risks and effects of substances should go back from 25 to 2.5 years. Through collaboration, sharing knowledge. The government could also do more to raise public awareness. Consumers who continue to buy non-stick pans and waterproof coats without worrying about the dangers allow manufacturers to continue as they were.'  

Government, the public, businesses and academics often point to each other when things get difficult. Who should take the lead?

'An interesting discussion; who is responsible for the system? Even in the case of decentralisation, the Government must establish frameworks. Municipalities have lobbied hard to be given their own responsibility and according to the Environment and Planning Act, they must take that responsibility. But when I look at the PFAS dossier, I wonder whether we can effectively tackle environmental problems with decentralisation. We have 350 municipalities, plus around 50 organisations like water boards, provinces and environmental departments. With good frameworks, with checks and balances, you can ask them to tackle the problem, but not if there is a lack of clarity about money, legal frameworks, risks and impact on the public. If the Government establishes those frameworks, decentralised parties can deliver custom work.' 'Another problem is the dissolution of the Technical Committee for Soil Protection in 2016. Now we do not have an organisation which gives the responsible Minister solicited and unsolicited advice, which identifies dangers and solutions. That is not something you can leave to private initiative. The Netherlands has several good laws, like the Decree on Soil Quality which regulates reuse of soil and ensures reliable products with little red tape. But dissolving that Committee - I don't understand that. 

Up the mountain

In 2013, Van Houten co-founded BodemBreed Forum, an association for soil professionals, from the self-employed to contractors, from academics to civil servants. 'It is a marketplace where you share knowledge and can discuss problems. Our themes are linked to societal challenges: energy transition, climate adaptation, circular economy and soil management of the future. We regularly organise meetings, some of which are well attended, others less so. Which is fine. Even ten people can do a lot of good. I had expected more members, but people prefer to take rather than give. That was something I saw at the Expertise Centre too. Perhaps young professionals don't think they have anything to contribute. But they know about things I've never heard of. Which is why we like to work together with organisations of young people who have just left the academy.'

What are some of the urgent issues in the soil world?

'Highlighting the importance of soil quality to society. Pollution spreads slowly in soil, unlike in water, but once it's there, it's hard to get rid of. To safeguard soil quality, there must be constant attention for it, at all levels. Management is invisible, but we must do it for years to come. Secondly, we must learn how to deal with new contaminants.’

You never feel that there is no end to the mountain of problems?

'Let's walk up the mountain and solve the problems one by one. Onward and upward.'  

Photo credits header: Bewust Bodem Gebruik | Liesbeth Sluier 2020
Text: Bewust Bodem Gebruik | Liesbeth Sluier 2020