Team:Aix-Marseille/Safety
For the first step of our project, realized this year, which is the proof of concept in E.Coli any parts and organisms are a biological danger. In fact, parts are taken from Formosa Agariphila and our chassi is E.Coli W3110 both are Risk Group 1.
For the second part of our project we have already thought about the different micro-organisms that are also Risk Group 1. For the degradation of algae: Saccharomyces cerevisae modified and for the fermentation: Pichia stipitis.
In this second part, we plan to include a genetic biocontainment system in our organisms in order to prevent survival of the GMO in the environment.
This year, we were unable to access the lab du to covid 2019. But each year Aix-Marseille Team’s before starting th lab work, have to do a biosafety and lab security workshop directed with Maialen CHABALIER (the Biosafety officer and technician of CNRS). The objective of the workshop was to ensure the well-being of students and to avoid injuries or contamination. The workshop also covered: laboratory access rules, general laboratory practices, personnel security equipment, chemical labelling, biohazard labelling and waste disposal. Safety procedures and practices include:
- A strict dress code: closed shoes, long pants, long sleeved lab coats, gloves, tied hair...
- Regularly disinfecting workbenches.
- Dedicating a specific workbench for manipulating potentially toxic chemicals (GelRed nucleic acid stain, polyacrylamide...).
- Wearing a safety mask and working under an extractor hood when manipulating volatile and/or toxic chemicals or organisms.
Offering everyone the safest possible working environment is a priority for the CNRS establishment. Thus, a prevention guide grouping health, safety, and environmental guidelines were always around. Safety was the pillar on which our work stood. Integrating the various procedures into our daily lab work facilitated our performance.
In literature1, high values of H2S have been detected, ranging from 22 mg/m3 to values greater than 1400 mg/m3! Ammonia was also present with other sulfur compounds such as Dimethylsulfide (DMS), or Dimethyldisulfide (DMDS), indicating a more advanced stage of alga decomposition.
Hydrogen sulfide is a very toxic gas affecting the human body in a lot of different ways. These effects mostly happen during single brief exposure to high concentrations of gas but some have also been reported during regular exposition to low concentrations2. Both of those scenarios are likely to happen with green tides as the workers cleaning the beaches and treating the algae are exposed for extended periods of time to the Freleased and, sometimes, to important peaks of concentration (regularly exceeding the lethal threshold)2.
Some of the most notable effects of hydrogen sulfide on the human body are :
- Ocular effects: At low concentrations (≤ 5mg/m3) the contact with the eyes may induce irritations, however a brief exposure to high concentrations (≤ 70mg/m3) can cause severe symptoms such as keratoconjunctivitis, punctate corneal erosion, blepharospasm, lacrimation, or photophobia3.
- Respiratory effects: Breathing high concentrations of hydrogen sulfide can have increasingly nefast repercussions on the respiratory system starting with minor discomforts (irritations of the respiratory tract causing such things as cough or shortness of breath)4 and possibly ending in bronchitis or even pulmonary oedema3.
- Neurological effects: One of the most insidious feature of this gas is the fact that, at concentrations exceeding 140 mg/m3, the victim who inhaled it will be struck by olfactory paralysis causing the loss of olfactory perception which can then lead to further unknowing inhalations3. In addition, high concentrations of H2S have been reported to cause other various detrimental effects going from nausea and headaches to loss of consciousness and convulsions.
- Cardiovascular effects: The inhalation of important quantities of H2S may also be responsible for various cardiovascular deficiencies (insufficient cardiac output, irregular heartbeat and conduction abnormalities)4. Moreover cardiovascular and neurologicals effects have been reported to last after the exposure ended, sometimes becoming permanents3.
- Metabolic effects: Hydrogen sulfide is able to inhibit the cytochrome oxidase enzyme system causing an oxygen deficiency in the cells. Those cells will then switch toward anaerobic reactions which cause an accumulation of lactic acid source of an acid-base imbalance. As the cardiac and neurological systems are particularly sensible to these kind of disruptions this explains why they are the ones suffering the most during an hydrogen sulfide intoxication4.
References:
- Pillard, Simon. "Mise au point sur les algues vertes : risques environnementaux et valorisations en 2016"
- "UVO de Lantic pour la valorisation d’une partie des ordures ménagères résiduelles en Côtes d’Armor".
- Chou, Selene J. Hydrogen Sulfide: Human Health Aspects. Concise International Chemical Assessment Document 53. Geneva: World Health Organization, 2003.
- "ATSDR - Medical Management Guidelines (MMGs): Hydrogen Sulfide Carbonyl Sulfide".