The Seveso dioxin leak is one of the major disasters that occurred in Europe in the 20th century. The disaster occurred in Meda, Italy, in 1976. A damaged valve at the ICMESA chemical plant led to the release of a cloud of smoke that contained toxic chemicals. The main poisonous chemicals that were in the fume included dioxin and trichlorophenol (EU, 2014).
The emission of these chemicals into the ambient environment led to air pollution, contamination of vegetation, and negative health effects. This paper will shed light on the types of exposures that occurred during the disaster, as well as the methods for detecting the relevant contamination. Also, the potential health effects of the exposures and the nature of the risk associated with the disaster will be discussed.
Types of Exposures
Exposure to toxic chemicals was the main risk associated with the Seveso dioxin leak. The smoke that was released into the atmosphere contained high levels of tetracholorodibenzoparadioxin (TCDD), which is a highly toxic type of dioxin (Gerber & Jensen, 2007). The toxic smoke covered a distance of nearly six kilometers in the Seveso region. As a result, 11 communities that had approximately 40,000 people were exposed to toxic chemicals through direct inhalation of the contaminated air.
Exposure to contaminated food was also a major aspect of the disaster. Thousands of farm animals inhaled the toxic fumes immediately after the accident. Besides, they ate plants that were contaminated with high levels of dioxin. Consequently, excessive amounts of dioxin were found in animal foodstuffs such as pork, meat, eggs, and milk (Doble & Kumar, 2005). This means that the public was exposed to the risk of food poisoning through eating contaminated animal food products.
The residents of Seveso were also exposed to waterborne diseases after the disaster. Some of the carcasses of the animals that died as a result of the accident were swept by rainfall into water bodies such as rivers (Assael & Kakosimos, 2010). Moreover, rainwater was contaminated due to the high concentration of dioxin in the air for several days. This increased the risk of an outbreak of waterborne diseases.
Methods of Detecting the Relevant Contamination
Over 90% of human exposure to dioxin occurs through the consumption of contaminated animal food products (EU, 2014). Thus, testing for dioxin contamination is mainly done on samples of suspected food products. However, quantitative chemical analysis of the level of contamination is often very difficult and expensive. Thus, the following sophisticated techniques have been developed to detect dioxin contamination.
The chemical analysis involves detecting various congeners of dioxin using “high-resolution gas-chromatography and mass-spectrometry (HRGC-HRMS)” (Chobtang et al., 2011, pp. 692-716). In this technique, an advanced clean-up process must be used to isolate the congeners of dioxin from other chemicals that are likely to interfere with the analysis of the samples. The main advantage of chemical analysis is that it provides excellent sensitivity that facilitates detection of dioxin in food products. However, the technique is expensive because it depends on sophisticated instruments, chemicals, and highly trained staff.
Bioassays involve using “living organisms or tissues that sense toxic substances to detect and quantify dioxin contamination in food and the environment” (Chobtang et al., 2011, pp. 692-716). Generally, bioassays determine the level of contamination through reporter gene expression. CALUX is one of the most effective cell-based bioassays that are used to monitor dioxin contamination in countries such as the US and Brazil. The advantage of cell-based bioassays is that they can detect low levels of dioxin contamination in food, water, and soil. Moreover, the technique is very effective since it uses a clean-up process that separates dioxin from other contaminants in the sample.
Biosensors are the main techniques that are used to detect the presence of dioxins in water, air, soil, animal feeds, and animal tissues. The main types of biosensors include immunosensors and whole cell-based biosensors (Tian & Zhao, 2012). Immonosensors depend on the use of antibodies to detect dioxins. Whole cell-based biosensors, on the other hand, use genetically engineered tissue cells to test for dioxin in soil and food samples. Although biosensors are cheap and easy to use, their ability to detect small quantities or low concentration of dioxin is limited.
Potential Health Effects of Exposure to Dioxin
Skin infections are the main short-term effects of exposure to dioxin. In Seveso, several children developed burn-like skin lesions immediately after the accident (Doble & Kumar, 2005). Although the lesions were painful, they did not cause deaths. Chloracne is the most severe skin disorder caused by ingesting food or inhaling air that is contaminated with dioxin.
Moreover, an individual can be infected by getting into physical contact with materials or plants that are contaminated with dioxins. The symptoms of the disorder usually emerge several weeks after exposure to dioxin. Approximately 193 cases of chloracne were reported in Seveso in the first two months after the disaster (Assael & Kakosimos, 2010).
The symptoms of chloracne include the appearance of several blackheads and whiteheads on some parts of the body. In most cases, the blackheads are accompanied by fluid-filled cysts. The blackheads usually appear in the cheekbone, armpits, groin, and behind the ears. Some chloracne patients normally develop excessive oiliness on their skin, as well as, sweaty palms and soles. Severe “chloracne may lead to open sores, permanent scars, and excessive growth of dark hair” (Assael & Kakosimos, 2010, p. 78). Moreover, the skin can become very thick and peel off — severe cases of chloracne cause extensive damage to the skin, which usually persists for a long time.
One of the long-term effects of exposure to dioxin is an increase in chronic diseases in the affected population. Specifically, exposure to dioxin is associated with an increase in cancer and diabetes. In Seveso, increased prevalence of type 2 diabetes and cancer was reported in the first five years after the accident. Exposure to dioxin also leads to respiratory and cardiovascular diseases. For instance, some residents of Seveso were found to have very high levels of fats circulating in their blood (hyperlipidemia).
Several empirical studies have indicated that exposure to dioxin can also cause sleep disturbance and abnormalities in the liver (Doble & Kumar, 2005). These diseases are normally difficult and expensive to treat. As a result, mortality rates usually increase substantially within the first five years after exposure to dioxin.
The prevalence of the aforementioned chronic diseases was relatively low in Seveso since the government of Italy took timely measures to clean-up the contamination. For instance, the affected vegetation was destroyed, whereas the soil was excavated and treated to reduce the level of contamination. Consumption of animal food products was also prohibited in the affected area, thereby preventing several people from eating contaminated food.
Excessive exposure to dioxin is associated with negative reproductive health effects. Dioxin is a hormone disrupter that interferes with human being’s ability to reproduce. Specifically, it causes a significant change in sex ratio. For instance, the proportion of male to female children that were born in Seveso before the accident was nearly equal. However, the sex ratio changed in favor of females after the first seven years of the accident. In particular, the parents who were exposed to high levels of dioxin had a higher number of female babies than male ones.
Exposure to dioxin is one of the major causes of spontaneous abortions (Assael & Kakosimos, 2010). It disrupts the secretion of thyroid hormone among pregnant women and the development of the foetus. Thyroid hormones play an important role in the body by regulating the metabolic rate and development of cells. Thus, an interference with the production of thyroid hormones among pregnant women leads to poor health conditions that eventually necessitate abortion. Exposure to dioxin also interferes with reproduction by causing impotence among men.
Immune System Disorders
Recent studies have linked exposure to dioxin to immune and neurological disorders. Dioxin weakens the immune system, thereby exposing the body to chronic diseases that eventually lead to premature deaths (Assael & Kakosimos, 2010). In Seveso, the children who were exposed to large amounts of dioxin had very weak immune systems.
This was illustrated by their high susceptibility to various infectious diseases such as coughs. Dioxin also negatively affects the neurological system by causing poor functioning of the nerve system. For instance, it leads to transient peripheral neuropathy among adults. This condition is associated with poor concentration and susceptibility to depression.
Nature of the Risk
The Seveso dioxin leak was an environmental risk since it mainly affected the neighboring communities rather than the employees of the company. Several factors exacerbated the environmental risks associated with the accident. To begin with, there were no employees at the factory at the time of the accident. Criminal investigations indicated that the accident occurred because of the negligence of the management and the employees of the factory who failed to take precautionary measures to avoid it (Gerber & Jensen, 2007). Besides, the emission of toxic fumes continued for several hours since there was nobody at the factory to stop it.
Second, the leak was not “accompanied by the kind of noise that would have alerted people to its presence” (Assael & Kakosimos, 2010). The only prominent sign of the accident was a cloud of smoke that rose above the factor. Since the local communities did not know the chemical reactions that took place at the factory, the smoke was ignored for several hours. As a result, toxic chemicals spread very fast through the strong wind. Overall, the chemicals contaminated an area of approximately 110 hectares.
One of the most significant environmental effects of the disaster was the death of thousands of farm animals. Nearly 4% of livestock died within the first week of the disaster. Investigations that were conducted by public health officers directly linked the death of the animals to dioxin poisoning (Gerber & Jensen, 2007). To avoid food positioning, over 100,000 farm animals that were suspected of having ingested dioxin were killed and disposed of safely. The toxic fumes also affected several plants in Seveso and other municipalities. The leaves of most trees began to wither immediately after the accident. The birds that got into contact with the affected plants were also poisoned by dioxin.
The fumes that were released from the factory contaminated the homes of the residents of Seveso and neighboring municipalities. Most residents reported that their houses were filled with smoke and unpleasant odor immediately after the accident. The people who stayed in their houses in the first night after the accident complained of severe headaches, nausea, vomiting, and swollen eyes (Doble & Kumar, 2005). These symptoms were directly linked to dioxin and other toxic chemicals that were emitted from the factory. Apart from contaminating the air, dioxin was deposited on walls, furniture, and materials within homes in the affected areas. This increased the exposure of the residents to dioxin through direct contact with contaminated materials.
The environmental effects of the Seveso dioxin leak were also observed in some European countries. During the clean-up process, the government of Italy contracted private companies that secretly shipped some of the contaminated materials to disposal sites in foreign countries. Most of the contaminated materials that left Italy have never been fully accounted for. However, some of the materials were found in San Quentin, France, in 1983 (Gerber & Jensen, 2007). This suggests that the dioxin from Seveso polluted the vegetation and water bodies in some parts of France, thereby exposing the public to chronic diseases. Poor regulation of the disposal of hazardous materials and corruption are the main factors that led to the disposal of the contaminated materials outside Italy.
The negative environmental effects of the accident reduced significantly in the last three decades. The factory and the homes that were seriously contaminated were demolished. Most of the materials from the factory and homes were buried in huge underground concrete tanks. Currently, water from the tanks is collected in a special container where dioxin contaminants are removed to prevent further contamination. The residents of the area were relocated, and the land where the factory was located was turned into a public park.
The Seveso dioxin leak had serious environmental and health problems in Italy. The accident led to contamination of buildings, vegetation, and water bodies. Several plants and animals died immediately after the accident due to excessive exposure to dioxin. Similarly, the people who were exposed to dioxin developed several diseases.
These included chloracne, cancer, diabetes, respiratory complications, and cardiovascular diseases. In this regard, the government of Italy should consider the following recommendations to prevent dioxin leaks in the future. First, tough regulations should be introduced to control the production of toxic chemicals such as dioxin.
The regulations should ensure that companies that produce poisonous substances have adequate measures to prevent industrial disasters. Second, hefty fines should be imposed on companies whose operations endanger the health of the public through unreasonable exposure to dioxin. This will motivate manufacturers of dioxin to behave ethically. Finally, the public should be educated on the risks associated with dioxin through awareness campaigns. Citizens are likely to monitor the activities of manufacturers if they are aware of the health and environmental risks that are associated with dioxin.
Assael, M., & Kakosimos, K. (2010). Fires, explosions, toxic gas dispersions: Effects. New York, NY: John Wiley and Sons.
Chobtang, J., Boer, I., Hoogenboom, R., Haasnoot, W., Kijlstra, A., & Meerburg, B. (2011). The need and potential of biosensors to detect dioxins and dioxin-like polychlorinated biphenyls along the milk, eggs, and meat food chain. Sensors 11(12) , 692-716.
Doble, M., & Kumar, A. (2005). Biotreatment of industrial effluents. London, England: Oxford University Press.
EU. (2014). Chemical accidents: Prevention, preparedness, and response.
Gerber, J., & Jensen, E. (2007). Encyclopedia of white collar crime. New York, NY: McGraw-Hill.
Tian, W., & Zhao, B. (2012). Immunoanalysis methods for the detection of dioxins and related chemicals. Sensors 12(1), 710-781.