Impact of Chemicals on the Environment, Animals and Humans’ Health. Case Study: Le Rhône

Romane LEJEUNE

Final Paper - GM0207

Impact of chemicals on the environment, animals and humans’ health. Case study: Le Rhône

Table of content

Presentation of the case        2

What’s PCB?        3

Potential exposure pathways        4

Today’s situation of the Rhône        5

Presentation of the case

The Rhône’s river is a river contaminated but in particular near the city of Lyon.

Around the city of Lyon, the principal sources of contamination are^[1]:

• Urban discharges emanated from wastewater treatment from households, companies…
• Agricultural discharges
• Industrial discharges

This last pollution is one of the most important because on more than 300km of waterway, there are two national routes, one highway, 6 railways, one oil and gas pipeline and other hydroelectric and nuclear factories. All of these have negative consequences on the quality of the water as well as on its environment.

The PCBs started to be used in France in the 1930’s in electrical transformer until we realised the risks for the populations and animals.

The situation is known since the 1980’s and the first analysis that shown the presence of PCB was made in 1986. In 2005, a surveillance programme was implemented on food quality, it was found that the level of PCB was really high in fish. Also, since 2005, it is forbidden to eat fish from the Rhône upstream Lyon because of the contamination from PCB (polychlorinated biphenyl). PCB in the Rhône have been detected at a rate 1,5 times superior to the regulatory limit fixed by the OMS.. In 2007, new tests were done on the fishes and it revealed a contamination by PCB higher than the limit allowed which is 8 picograms (=10−12 gram) per gram of fresh fish. This results in an extension of the zone where people cannot eat the fish from the Rhône. Today, nine departments are concerned: Ain, Ardèche, Bouches-du-Rhône, Drôme, Gard, Isère, Loire, Rhône, Vaucluse. Approximately 180 industrial factories are suspected to contaminate the ground and to discharge in the water as a source of PCB release in the Mediterranean Basin and the region Rhône-Alpes.

Through this case we will see how the historic usage of PCB by the industries near the Rhône creates negative externalities and also a case of tragedy of the commons.

What’s PCB?

^[2]Polychlorinated biphenyl or pyralenes are complex compound used by the industry since the 1930’s for their isolation attribute (electrical transformers), their chemical stability (paint). Not much biodegradable, they accumulate gradually in the environment in particular in certain reservoirs as marine sediments or river.

PCB was discovered in 1865, between then and 1914, large amount of PCBs was released into the environment. In 1935, PCBs started to be massively commercialised by American companies. In the 1930s, the toxicity associated with PCBs and other chlorinated hydrocarbons was recognized because of a variety of industrial incidents. Following this several medical cases and papers released on the possible link between PCBs and its detrimental health effects.

Today, we can find PCB in French people blood. The French Agency of sanitary safety of food estimated the balance profits/risks bound to the consumption of fish. This balance depends not only on the consummate quantity, but also on the choice of the species and on their origin. Most of the PCB are probably carcinogenic, endocrine disruptors and/or enzymatic inductors susceptible to disturb the metabolism.

Collective intoxication (ex:Japan) showed 1800 persons contaminated were having skin rashes, digestive and eye disorders(confusions), numbnesses of limbs. Professional intoxications resulted with skin reactions like acne, hyperpigmentation, keratosis, but also a general fatigue, anorexia, a loss of weight, a hepatic infringement, or bronchitis. There can be risks for a baby if the woman is pregnant and is assimilating too much PCB.

In all the compartments ground and water, as well as in the ecosystems, the PCB are among the most frequent, the most present and the most long-lasting pollutants, which let’s expect future serious and badly anticipated problems. The scientists had however shown or noticed that these molecules being little biodegradable, and very soluble in oil and vegetable or animal fats.

It has been proved that their rejection in the environment was massive, and that it led to a phenomena of bioaccumulation for the wild and breeding fauna and for the human health.

Therefor, in the sea, the cetaceans (among which sperm whales, killer whales, porpoises and dolphins), as well as diverse fishes of the summit of the food chain (tuna, swordfish, etc.) can bio-concentrate these products. The eel, that is a fish mainly made of fat is also very affected.

For these reasons, since the 1990s, the PCB are among persistent organic pollutants, which production is forbidden in the agreement of Stockholm on persistent organic pollutants.

Potential exposure pathways

Humans and wildlife can be exposed to PCBs either directly from contact with contaminated air, sediments, or water or indirectly through the diet.

Bioaccumulation—The net accumulation of PCBs by an organism as a result of uptake from all routes of exposure (i.e., water, sediment, food, or air).

Bioconcentration—The net accumulation of PCBs directly from water by aquatic organisms (Suter 1993).

Food Web Transfer—The movement of PCBs in the tissue of prey to the tissue of the predator, repeated one or more times in the food web, where the predator of the first transfer is the prey in the next step.

Biomagnification—The tendency of PCBs to accumulate to higher concentrations at higher levels in the food web through dietary accumulation.

Bioavailability—The ratio of the amount of PCBs taken into the organism and thus available to internal tissues, compared to the amount of PCBs ingested into the gut, inhaled into the lungs, or in direct contact with the skin.

When considering exposure pathways, it is imperative to assess the biologically available fraction of PCBs. In sediments, PCBs can be buried below the biologically active zone and, therefore, are less available for uptake by aquatic organisms. The biologically active zone is the top layer of sediments, typically 5–10 centimeters deep. This layer is continuously reworked by sediment-dwelling organisms and remains in contact with the overlying water. PCBs that are strongly sorbed to organic sediment particles in the biologically active zone tend to have reduced bioavailability to organisms that ingest or are exposed to these sediments.