Polychlorinated biphenyls (PCBs) are synthetic molecules used in many industrial applications until they were banned due to their toxicity and their very persistent nature in the environment.
Considered to be a substance of great concern for health and the environment, the health authorities recommend limiting these extremely harmful substances to a minimum for humans.
Banned since the 1970s in the United States and 1980s in Europe, humans are now mainly exposed to them through their diet. However, some industrial activities continue to emit these highly toxic pollutants.
What have been the main uses of PCBs?
PCBs are organochlorine chemical compounds of the biphenyl family.
Depending on the number and position of the chlorine atoms, there are exactly 209 possible congeners. Marketed under the names pyralene or aroclor, the formulations do not include anyone but a limited number of congeners, accounting for more than 95% of the PCBs produced.
Because of their properties as electrical insulators and flame retardant additives, they have been used since the 1930s, particularly in :
- Electrical installations such as transformers and capacitors
- Cooling and hydraulic systems
- Mineral oils
- Microwave ovens, some adhesives and paints
Banned in France since 1987, anyone including PCBs poses a significant risk to humans and the environment.
Today, it is the management of waste that still poses a major problem in terms of the emission of these toxic substances.
What are the main sources of exposure to PCBs?
Apart from exposure from a particularly PCB-polluted environment, the main source of exposure to PCBs is food.
PCBs are very persistent in the environment, i.e. they are very stable and degrade extremely slowly. This property favours their presence in anyone from the depths of the oceans to the tops of the highest mountains.
Once ingested by a living organism, PCBs are not easily metabolised, i.e. they are not easily transformed by the body and eliminated in the urine.
PCBs are lipophilic, i.e. they are soluble in fat and fix themselves durably in fatty tissues and accumulate there over time. They will thus move up the food chain to humans.
Large fatty fish (tuna, salmon, etc.), fatty meat, dairy products and eggs are the most contaminated foods. Their consumption is the main source of dietary exposure.
The authorities recommend that pregnant or breastfeeding women limit their consumption of fatty fish.
Which industrial activities emit PCBs?
Before the ban, the main producers of PCBs were Austria, China, Czechoslovakia, France, Germany, Italy, Japan, the former USSR, Spain, the UK and the USA.
The production sites are potentially heavily polluted by these chemicals.
Apart from this so-called historical pollution, PCB emissions are mainly related to the treatment of waste including PCBs.
The combustion of waste in incinerators.
As they are resistant to very high temperatures, they are not destroyed during the incineration of waste. They are released into the environment with the incineration fumes, which are nowadays treated with efficient filtration systems.
European regulations require the monitoring of PCB emissions and compliance with defined emission thresholds. These controls are carried out by the authorities and "self-monitoring" is also required from the industry.
Living near an incinerator and under the prevailing winds can expose residents to PCBs.
Decontamination of industrial equipment.
PCBs are widely used in electrical installations for their electrical insulating and fireproofing properties, but they are present in very large quantities in this equipment and present a very high pollution risk.
The regulations are very heavy for companies specialising in the treatment of this type of waste.
However, it has not prevented significant pollution in the vicinity of the APROCHIM company of the CHIMIREC group, which specialises in the treatment of hazardous waste and is located in the Mayenne region between Laval, Le Mans and Angers.
Living near a waste treatment site including PCBs can expose local populations if the company does not respect emission standards or if an industrial accident occurs and releases large quantities of PCBs into the environment.
Management of contaminated soil.
Soil contaminated with PCBs at a level of more than 1 mg/kg (sum of the concentrations of 7 PCBs, PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, PCB180) is considered polluted.
They must be stored in facilities specifically designed for the management of hazardous and non-hazardous waste.
Living in a building (home or workplace) built on PCB-contaminated soil exposes the occupants to PCBs through inhalation of contaminated dust or through ingestion of food produced on contaminated soil.
Recycling of materials.
Some landfill materials include PCBs but are not necessarily identified as such. They can therefore be recycled as part of a sustainable development approach.
Plastic materials may include flame retardants such as PCBs. They can therefore be reused to produce new plastic materials, which can lead to the spread of PCBs in our daily environment.
The recycling of metals in installations with metal shredders is also a source of environmental pollution by PCBs, as has been noted in Belgium by the Walloon health authorities.
Investigations by the Federal Agency for the Safety of the Food Chain (AFSCA) have shown that PCB contamination of foodstuffs intended for animal feed has occurred in farms located near the COMET-SAMBRE metal shredder in Obourg, near Mons.
This problem concerns anyone in the metal shredding industry and on Belgian territory, particularly for :
- COMET SAMBRE site in MONS (Obourg)
- COMET SAMBRE site in CHATELET
- DERICHEBOURG BELGIUM site in CHARLEROI (Marchienne-au-Pont)
- KEYSER ET FILS site in COURCELLES
- ECORE BELGIUM site in AUBANGE
- BELGIAN SCRAP TERMINAL WALLONIE (BST) site in ENGIS
- DUBAIL site in NAMUR (Beez)
These companies have been granted deadlines to meet the emission standards for PCBs and heavy metals.
How to measure your exposure to PCBs?
PCBs present in the body are incorporated into the structure of the hair when they are synthesised in the scalp. The hair thus bears the trace of daily exposure to PCBs and the analysis of each centimetre of hair provides information on the average exposure over a period of 1 month.
The level of PCBs in the hair is an indicator of a person's exposure level.
Hair analysis is very well suited to the assessment of PCB exposure and has been used in many scientific studies to establish the levels of impregnation of populations.
To be comprehensive, the analysis should cover at least the 6 Indicator PCBs and the 12 Dioxin-Like PCBs and ideally the list of the 32 main PCBs including the Indicator PCBs and the Dioxin-Like PCBs.
PCB Hair Analysis
PCB exposure analysis. Order your TestSources :
Pollution in the vicinity of metal shredders in Wallonia
Overview of the main air emissions in the Loire region
PCB contamination of the natural environment: knowledge of the pollutant and clean-up techniques