About

To get insight into local environmental challenges, we contacted Anne-Sophie Allonier Fernandes, expert and project manager of water and health at the Eau Seine-Normandie agency. Her team manages the pollutant monitoring of over 800 micropollutants in the natural environments of the Paris and Normandie area. Her goal is to ensure pollutant concentrations remain below a reglementary threshold and to alert authorities in case of an anomaly.

Fig 1: Anne Sophie Allonier Fernandes

Monitoring local pollutants

Sampling

"The main challenge, is the number of microchemicals that need to be monitored" she told us, "the numbers of chemicals introduced in industry and rejected into the wild are in exponential explosion". She told us how little is known about the effects of these chemicals on the natural environment and human health. Her team assess which are the main chemicals to be measured and delegates the sampling and laboratory testing to specialised groups. The testing needs to be done in accredited laboratories to detect chemicals under a certain threshold.

All regulations procedures are done in the lab, and she informs us that very little monitoring is done in situ. The frequency of samples taken is usually every month, a "photo", as she calls it. This kind of monitoring can detect very low concentrations, but does not account much for variability. Very little automation exists for monitoring pollutants, and of the data collection demands a lot of man-power, which limits the frequency of samples.

Safety

Integration

When an anomaly in pollution is detected, such as a chemical spill for example, Anne-Sophie and her team will alert the water police who will proceed with an investigation. We asked her whether faster and more frequent detection could help in these procedures. She replied that that would be useful only if there is a way to create barriers or deviate the water flow. She suggested that it would be useful to have our detection system just downstream of an industrial plant, where an alert could be raised and the waste can be halted immediately. She emphasized the ability to act on our alert, because water flow is not easy to stop. Our system could work as a pre-treatment before the water is released into the natural environment.

Talking with Anne-Sophie helped us to understand the current means to monitor pollutants in aqueous environments. The increasing number of pollutants to be detected made us conceive of ways to make biosensors that are both electronic, but who's sensing capabilities can be interchanged. This is how we thought of splitting the biosensor into the processing unit on one plasmid which will trigger the expression of the electronic reporter gene on the second. This way, a library of biosensor processors can be created without needing the electronic reporter plasmid to change.

Anne-Sophie informed us that in the past, in France, people used to put fish in the drinking water and if they die, people would not drink the water. Thankfully, we have toxicology tests that are much more sensitive and ethical than this today, but we nevertheless thought that a similar process with bacteria could exist. Using a biosensor gene-lysis gene, the triggering of death would release ions in the medium which could be read as a conductivity measure. Having an electrical signal also has the advantage of being easily connected to other machines, for example a connection to an industrial waste valve that can close. This could allow a reactivity that is much faster and does not require human intervention to proceed.