Seveso Accident Research Articles

Mortality and cancer incidence in a population exposed to TCDD after the Seveso, Italy, accident (1976–2013)

ObjectivesThe Seveso accident (1976) caused the contamination with 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) in an area north of Milan, Italy. We report the results of the update of mortality and cancer incidence in...

Age at menarche in Seveso daughters exposed in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

In 2014, nearly 40 years after the explosion, we enrolled postexplosion offspring, 2 to 39 years of age, in the Seveso Second Generation Study. Age at onset of menarche (years) was collected for 316 daughters by maternal report or self-report at interview. In utero TCDD exposure was defined by maternal TCDD serum concentrations extrapolated to the pregnancy. At interview, 287 daughters were postmenarche and reported age at menarche averaged 12.1 years (±1.3 years). Overall, we found no change in risk of menarche onset with a 10-fold increase in in utero TCDD exposure (hazard ratio [HR] = 0.86; 95% confidence interval [CI] = 0.71, 1.04). When we considered maternal menarche status in 1976 as a potentially sensitive developmental exposure window, in utero TCDD (log10) was associated with later age at menarche among daughters whose mothers were premenarche (HR = 0.71; 95% CI = 0.52, 0.97) but not postmenarche (HR = 0.89; 95% CI = 0.71, 1.12) at the time of the explosion (P int = 0.24). These results suggest that in utero TCDD exposure may alter pubertal timing among daughters of women who were prepubescent at the time of the Seveso accident.

Application of a gaussian model to simulate contaminants dispersion in industrial accidents

The increase of the industrial production and the development of new processes led to the necessity of better regulations of activities concerning potential risks for human health and environment. Accomplishing such purposes requires studies on both the chemistry of the involved phenomenon and the dispersion mechanism in the surrounding environment. While the chemistry of reaction can be determined at small scale via laboratory experiments and models, the dispersion in the environment is an extremely complex phenomenon to model, because it is strongly affected by the atmospheric conditions. Several models with the purpose of simulating pollutants dispersion were developed (Gariazzo et al., 2012; Alemayehu et al., 2015; Fang et al., 2018); among those, Gaussian models found many applications in safety engineering, due to both their effectiveness and relatively low computational costs. The US-EPA recommends the use of the Gaussian model AERMOD for the simulation of dispersions within 50 km from the emission source. It is important to underline that most of these models were developed with the aim to simulate the dispersion of continuous emissions such as those from industrial chimneys. Such systems can be assumed to work under steady-state conditions, since they are supposed to work for a long time. Nonetheless, industrial accidents, which can have a severe impact on people and environment, generally occur at a relatively small time scale, thus their dispersion has not yet reached the steady state conditions.In this work, we developed a modified non-steady-state Eulerian Gaussian model able to simulate the dispersion of contaminants produced by an industrial accident, which is hypothesized to be a point source. The model requires as input data time-dependent meteorological conditions and topographic information of the site, concerning: the source, physical properties of the pollutant, emission height and release temperature. The proposed model was applied to the 2,3,7,8-Tetrachlorodibenzodioxin (TCCD) dispersion after the Seveso accident (1976) near the source (radius of about 4 km). Results highlighted a good agreement with available literature experimental data.

In Utero Dioxin Exposure and Age at Menarche in the Seveso Second Generation

Introduction: In utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a widespread environmental contaminant and potent endocrine disrupting compound, is associated with delayed pubertal development in animal studies. On July 10, 1976, an explosion at a chemical plant near Seveso, Italy exposed nearby residents to high levels of TCDD. The Seveso Women’s Health Study (SWHS), initiated in 1996, is the only study to date of TCDD’s health effects in a female population with the unique benefit of individual TCDD measured in blood collected near the time of the explosion. In 2014, we enrolled SWHS offspring (those exposed in utero to TCDD) in the Seveso Second Generation study. We examined the relationship of in utero TCDD exposure with reported age at onset of menarche among SWHS daughters.Methods: Age at onset of menarche (in years) was collected by maternal or self-report at interview in 341 SWHS daughters. We defined in utero TCDD exposure as initial (1976) maternal serum TCDD level and TCDD extrapolated to pregnancy. Data were analyzed using Cox proportional hazards models.Results: At interview, 287 daughters were postmenarche, averaging 25.6 (±8.0) years of age. The mean reported age at menarche was 12.1 (±1.3) years. Overall, we found no change in risk of menarche onset with a 10-fold increase in initial maternal TCDD (Hazard Ratio (HR) = 0.91, 95% CI 0.79, 1.06) or TCDD estimated at pregnancy (HR = 0.86, 95% CI 0.72, 1.03). When we considered maternal menarche status at explosion as a potentially sensitive developmental exposure window, TCDD estimated at pregnancy (log10) was associated with later age at menarche among daughters whose mothers were premenarche at explosion (HR = 0.71, 95% CI 0.50, 1.00) but not postmenarche at explosion (HR = 0.87, 95% CI 0.71, 1.07).Conclusions: These results suggest in utero exposure to TCDD may alter pubertal timing among daughters of women who were prepubescent at the time of the Seveso accident.

A perspective on Seveso accident based on cause-consequences analysis by three different methods

Seveso incident happened on Saturday 10th July 1976 within the production plant of 2,4,5-trichlorophenol at the ICMESA factory represents a watershed because it gave off a specific legislation in the field of safety regarding activities subjected to Major Accident Hazards (MAH) and the handling of dangerous substances. Although the severity of the mishap, still nowadays the real cause of the accident remains, at least partially, shrouded in uncertainty and different mechanism hypotheses were proposed. These doubts could lead considering Seveso mishap as a “black swan” incident, i.e. an improbable event characterized by three peculiarities: it is not expected; it has an extreme impact; it is explainable and predictable after the fact. Further investigation appears to be essential, analyzing the available material and processing a deep analysis towards several methods, which provide different views and interpretations of the fact. To this purpose, three methods were selected: AcciMap approach; the Energy Barrier Model; the System-Theoretic Accident Model & Processes (STAMP) coupled with a dynamic approach. The last part of this work is dedicated to a specific modelling of the incident through system dynamics technique using a customized framework covering technical, human and organizational aspects.

HazMat transportation risk assessment: A revisitation in the perspective of the Viareggio LPG accident

The Seveso accident triggered a virtuous process towards the development of methods, models and tools for safety and risk assessment and management. Among the more relevant results of such process was the stemming of methods and tools addressing the transportation of hazardous substances in the framework of a holistic approach to the control of major accident hazards related to dangerous substances. The present study aims at the analysis of reference procedures and tools available for the analysis of the risk in the transportation of dangerous substances in the light of the Viareggio accident. The Viareggio accident represents a paradigmatic event involving the transportation of dangerous substances. The accident, that took place in Italy in 2009, was analyzed in the perspective of current approaches to the analysis of risk in the transportation of hazardous materials. The results pointed out that the Viareggio scenario, although of particular severity, is comprised within those accounted in quantitative risk analysis.

Industrial disasters: the Seveso accident and its 40-year legacy

The 1976 disaster in Seveso, Italy left a legacy of utmost relevance and contributed to a major shift in the way society, people and industry consider the environment-and-health issue. Main aspects of this legacy concern policy, science, research and the community. Policy: The accident prompted the adoption in 1982 of EU legislation on the prevention and control of major-accident hazards of certain industrial activities, the ‘Seveso-Directive’, later amended in 1996 and in 2012 to take into account increased rights for citizens to access information and justice. Science: The accident represented an unplanned ‘experiment’ providing further insight into the effects of 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD) in humans. An increased risk was seen for lymphohematopoietic neoplasms in the thirty-year post-accident period; all-cancer incidence was increased in a subset of highly exposed women; suggestive, non-consistent increases were seen for colorectal and breast cancer. Diabetes was more frequent in the exposed area. In families with very high TCDD serum concentrations, the M/F ratio at birth was inverted; the number of females being larger than males. The male reproductive system appeared critically sensitive to TCDD. Women’s fertility and second generation studies are underway. Research: Seveso made it clear that for a complete health impact assessment, in addition to chemical exposure, the post-disaster stressful experience, the personal and community characteristics and the measures implemented to respond to the disaster should be considered: The increased cardiovascular mortality among men in the most polluted area, in the early post-accident period, points towards post-disaster stress as a major health determinant. Community: People need not only to be protected, but also to play an active role in the response and recovery phases. Communication and participation avoid mistrust, control stressful factors and foster population resilience.

Levels and sources of PCDDs, PCDFs and dl-PCBs in the water ecosystems of central Poland - a mini review.

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are unwanted by-products in a variety of industrial and thermal processes. They have been present on Earth long before the human era, since they may be also formed as a result of forest fires or volcanic explosions. Polychlorinated biphenyls (PCBs) in turn, have been intentionally produced by humans. Poland was a minor producer of PCB mixtures (Chlorofen and Tarnol), which were a source of direct and indirect environmental diffusion with PCB and less with PCDDs/PCDFs. Industrial accidents with PCDDs/PCDFs were absent in Poland. Their stability and resistance to thermal breakdown made them very dangerous for environment and, in consequence, due to their environmental persistence, bioaccumulation and biomagnification in the terrestrial and aquatic food chains, to humans. Humans may become affected by PCDDs/PCDFs and PCBs through environmental (soil and water contamination, fish and food), occupational (incinerators; pulp, paper and metallurgy industry; copper production), or accidental (Seveso accident) exposure. The aim of this review was to evaluate environmental hazard caused by PCDDs, PCDFs and dioxin-like-PCBs in the central region of Poland based on the accessible data on diffusion of those compounds in sediments and riverine, reservoir and storm water from our previous studies and discussed in the context of other achievements in Poland and elsewhere.

Associations of Exposure to Dioxins and Polychlorinated Biphenyls with Diabetes: Based on Epidemiological Findings

Persistent organic pollutants (POPs) are a group of chemical substances that have the common properties of resistance to biodegradation, wide-range transportation, high lipophilicity, bioaccumulation in fat, and biomagnification in the food chain. POPs are persistent in the environment worldwide and have potential adverse impacts on human health and the environment. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) are well known chemicals that are considered as POPs. The association between high-level exposure to dioxins and type 2 diabetes among U.S. Air Force veterans who had been exposed to Agent Orange contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during the Vietnam War was reported in the late 1990s. This association has been supported by similar epidemiologic studies, whose subjects were exposed to high doses of dioxins in their places of work involving phenoxyacid herbicide production and spraying, and in the industrial accident in Seveso, Italy. Recently, low-level exposure to dioxins and PCBs has been reported to be linked to type 2 diabetes. Cross-sectional studies in the U.S. general population and Japanese general population showed that body burden levels of some dioxins and PCBs were strongly associated with the prevalence of type 2 diabetes. Very recently, following these cross-sectional studies, several prospective studies have suggested that low-level exposure to some PCBs predicted the future risk of type 2 diabetes in the general population. Environmental exposure to some dioxins and PCBs, which mainly accumulate in adipose tissue, may play a role in the development of type 2 diabetes.

Congenital Hypothyroidism with Gland in situ is More Frequent than Previously Thought

OPINION article Front. Endocrinol., 15 February 2012Sec. Thyroid Endocrinology https://doi.org/10.3389/fendo.2012.00018

Development of chemical accident database: Considerations, accident trend analysis and suggestions

Traditionally, regulations, standards, codes and management systems were established after major accidents such as Seveso Directive by Seveso accident, Italy, in 1976, etc. Also, several chemical material and process accident databases were developed and implicated in the world. In this paper, we introduce a set of recently developed databases, such as eMARS (EC), HSEES (USA) and PEC-SAFER (Japan), and describe current development of a chemical accident tracking system in Korea. Especially, we intensively focused on general classification codes, simplified and effective database structure, user friendly interface and intuitional searching methods. Additionally, the chemical accident trends were analyzed by using third grade of accident casualties and property’s loss. Finally, suggestions for applicability improvement of database are proposed. To improve the management and operability of hazardous materials and chemical processes, the systemic approaches are essential using accident database. The developed database and suggested issues in this study can perform an important function in the chemical industries.

Lymphohemopietic neoplasms and dioxin exposure in the Seveso cohort 30 years after the accident (1977–2006)

ObjectivesThe Seveso accident caused the contamination of a large inhabited area by 2,3,7,8-tetrachlorodibenzodioxin. Three zones with decreasing soil TCDD levels were delimited: A, B and R. Persons ever living in...

Perinatal Exposure to Low Doses of Dioxin Can Permanently Impair Human Semen Quality

BackgroundIn recent decades, young men in some industrialized areas have reportedly experienced a decrease in semen quality.ObjectiveWe examined effects of perinatal dioxin exposure on sperm quality and reproductive hormones.MethodsWe investigated sperm quality and hormone concentrations in 39 sons (mean age, 22.5 years) born between 1977 and 1984 to mothers exposed to dioxin after the accident in Seveso, Italy (1976), and 58 comparisons (mean age, 24.6 years) born to mothers exposed only to background dioxin. Maternal dioxin levels at conception were extrapolated from the concentrations measured in 1976 serum samples.ResultsThe 21 breast-fed sons whose exposed mothers had a median serum dioxin concentration as low as 19 ppt at conception had lower sperm concentration (36.3 vs. 86.3 million/mL; p = 0.002), total count (116.9 vs. 231.1; p = 0.02), progressive motility (35.8 vs. 44.2%; p = 0.03), and total motile count (38.7 vs. 98 million; p = 0.01) than did the 36 breast-fed comparisons. The 18 formula-fed exposed and the 22 formula-fed and 36 breast-fed comparisons (maternal dioxin background 10 ppt at conception) had no sperm-related differences. Follicle-stimulating hormone was higher in the breast-fed exposed group than in the breast-fed comparisons (4.1 vs. 2.63 IU/L; p = 0.03) or the formula-fed exposed (4.1 vs. 2.6 IU/L; p = 0.04), and inhibin B was lower (breast-fed exposed group, 70.2; breast-fed comparisons, 101.8 pg/mL, p = 0.01; formula-fed exposed, 99.9 pg/mL, p = 0.02).ConclusionsIn utero and lactational exposure of children to relatively low dioxin doses can permanently reduce sperm quality.

Long-term Effects in the Population Exposed to Dioxin After the “Seveso Accident”

Long-term Effects in the Population Exposed to Dioxin After the “Seveso Accident”

Cancer incidence in the population exposed to dioxin after the "Seveso accident": twenty years of follow-up.

BackgroundThe Seveso, Italy accident in 1976 caused the contamination of a large population by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Possible long-term effects have been examined through mortality and cancer incidence studies. We have updated the cancer incidence study which now covers the period 1977-96.MethodsThe study population includes subjects resident at the time of the accident in three contaminated zones with decreasing TCDD soil levels (zone A, very high; zone B, high; zone R, low) and in a surrounding non-contaminated reference territory. Gender-, age-, and period-adjusted rate ratios (RR) and 95% confidence intervals (95% CI) were calculated by using Poisson regression for subjects aged 0-74 years.ResultsAll cancer incidence did not differ from expectations in any of the contaminated zones. An excess of lymphatic and hematopoietic tissue neoplasms was observed in zones A (four cases; RR, 1.39; 95% CI, 0.52-3.71) and B (29 cases; RR, 1.56; 95% CI, 1.07-2.27) consistent with the findings of the concurrent mortality study. An increased risk of breast cancer was detected in zone A females after 15 years since the accident (five cases, RR, 2.57; 95% CI, 1.07-6.20). No cases of soft tissue sarcomas occurred in the most exposed zones (A and B, 1.17 expected). No cancer cases were observed among subjects diagnosed with chloracne early after the accident.ConclusionThe extension of the Seveso cancer incidence study confirmed an excess risk of lymphatic and hematopoietic tissue neoplasms in the most exposed zones. No clear pattern by time since the accident and zones was evident partly because of the low number of cases. The elevated risk of breast cancer in zone A females after 15 years since the accident deserves further and thorough investigation. The follow-up is continuing in order to cover the long time period (even decades) usually elapsing from exposure to carcinogenic chemicals and disease occurrence.

Inherent safety of substances: Identification of accidental scenarios due to decomposition products

The hazard due to the unwanted formation of dangerous substances in the loss of control of a chemical industrial process is well known since the Seveso accident. The assessment of the inherent hazards related to the loss of control of a chemical process should include as well the identification of the hazards associated to the emission of possible products of unwanted reactions. This issue is among those that still need to be addressed in the design of inherently safe chemical processes. In the present study, a new approach was developed to screen the hazard profile of the unwanted products that may be formed as a consequence of process deviation from normal operating conditions. Three different categories of hazards were taken into account: acute and long-term hazard for humans, damage to ecosystems, environmental media contamination. The method allows the definition of a hazard footprint of the unwanted product mixture, and of four indices, each characterizing the potential impacts of release scenarios with respect to a specific category of hazards: acute toxicity, chronic toxicity, carcinogenicity and ecotoxicity. The four impact indices allow the identification of the more hazardous accidental scenarios that may derive from the loss of containment of the unwanted products during an accidental event. As confirmed by several case-studies, the application of the approach developed, coupled with an array of experimental protocols for the identification of the products formed under accidental conditions, results a useful tool for the screening of the potential hazards related to the formation and release of unwanted products in “out of control” conditions.

Dioxin Exposure and Cardiovascular Disease: An Analysis of Association

Vol. 116, No. 11 EnvironewsOpen AccessDioxin Exposure and Cardiovascular Disease: An Analysis of Association Valerie J. Brown Valerie J. Brown Search for more papers by this author Published:1 November 2008https://doi.org/10.1289/ehp.116-a491bAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Dioxins have long been known as highly toxic compounds, having been implicated in cancer, immune system disorders, endocrine disruption, and birth defects. Animal and in vitro studies have also suggested a role for dioxins in heart disease. Now a systematic review of epidemiologic studies has found an association between dioxin exposure and death from cardiovascular diseases, particularly ischemic heart disease (reduced blood supply to the heart) [EHP 116:1443–1448; Humblet et al.].The authors reviewed all English-language studies on dioxin exposure and death from cardiovascular disease reported in PubMed as of December 2007. They used a broad definition of “dioxins” that included polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) with dioxin-like effects, and polychlorinated dibenzo-p-dioxins (PCDDs). However, they excluded studies that focused primarily on PCBs because results pertaining to the non–dioxin-like members of this family would muddy the interpretation of dioxins’ cardiovascular effects. Likewise, studies of occupational exposure in the leather processing and flavor/fragrance industries were excluded because workers in these industries are exposed to cardiotoxic methylmercury, arsenic, and xylene along with dioxin.The remaining studies included 12 dioxin-exposed cohorts, one of which was a large multicenter cohort study; 10 of these cohorts involved military or occupational dioxin exposure, and 2 involved environmental exposure of the general public. The cohorts included Vietnam veterans exposed to herbicides; the population of Seveso, Italy, exposed in 1976 by an industrial accident to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic dioxin; and a Taiwanese population exposed in 1979 to polychlorinated dibenzofurans in rice oil.The researchers identified numerous potential limitations in the reviewed studies. For example, none of the studies adjusted for all the known cardiovascular risk factors of diet, smoking, physical activity, family history, and body mass index, so residual confounding was a concern. Furthermore, not all studies made internal comparisons between lowest-exposed and highest-exposed members of a cohort. Some compared the exposed cohorts with the general population, which may confound results because of the “healthy worker effect” (that is, workers as a group are typically healthier than the general population, which includes those who are too ill to work). There was also wide variation in the precision of exposure estimates.Despite these potential limitations, the authors concluded that the literature as a whole presented reasonable evidence that dioxin exposure at high doses raises the risk of death from heart disease. They suggest the need for further studies that account for the limitations in the existing studies, particularly with respect to confounders, choice of comparison populations, and environmentally relevant exposure concentrations.After the 1976 Seveso accident involving TCDD, an official posts a sign warning residents not to touch or eat garden produce and to avoid contact with vegetation, soil, and grass.FiguresReferencesRelatedDetails Vol. 116, No. 11 November 2008Metrics About Article Metrics Publication History Originally published1 November 2008Published in print1 November 2008 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Neonatal Thyroid Function in Seveso 25 Years after Maternal Exposure to Dioxin

BackgroundNeonatal hypothyroidism has been associated in animal models with maternal exposure to several environmental contaminants; however, evidence for such an association in humans is inconsistent. We evaluated whether maternal exposure to 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a persistent and widespread toxic environmental contaminant, is associated with modified neonatal thyroid function in a large, highly exposed population in Seveso, Italy.Methods and FindingsBetween 1994 and 2005, in individuals exposed to TCDD after the 1976 Seveso accident we conducted: (i) a residence-based population study on 1,014 children born to the 1,772 women of reproductive age in the most contaminated zones (A, very high contamination; B, high contamination), and 1,772 age-matched women from the surrounding noncontaminated area (reference); (ii) a biomarker study on 51 mother–child pairs for whom recent maternal plasma dioxin measurements were available. Neonatal blood thyroid-stimulating hormone (b-TSH) was measured on all children. We performed crude and multivariate analyses adjusting for gender, birth weight, birth order, maternal age, hospital, and type of delivery. Mean neonatal b-TSH was 0.98 μU/ml (95% confidence interval [CI] 0.90–1.08) in the reference area (n = 533), 1.35 μU/ml (95% CI 1.22–1.49) in zone B (n = 425), and 1.66 μU/ml (95% CI 1.19–2.31) in zone A (n = 56) (p < 0.001). The proportion of children with b-TSH > 5 μU/ml was 2.8% in the reference area, 4.9% in zone B, and 16.1% in zone A (p < 0.001). Neonatal b-TSH was correlated with current maternal plasma TCDD (n = 51, β = 0.47, p < 0.001) and plasma toxic equivalents of coplanar dioxin-like compounds (n = 51, β = 0.45, p = 0.005).ConclusionsOur data indicate that environmental contaminants such as dioxins have a long-lasting capability to modify neonatal thyroid function after the initial exposure.

Dioxin and Effects on Human Reproductive System: Data from Seveso Accident.

Dioxin and Effects on Human Reproductive System: Data from Seveso Accident.

Mortality in a Population Exposed to Dioxin after the Seveso, Italy, Accident in 1976: 25 Years of Follow-Up

The Seveso accident in 1976 caused a large, populated area north of Milan, Italy, to be contaminated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In this study, the authors followed up the exposed population for chronic effects; this paper reports the results of the mortality follow-up extension for 1997-2001. The study cohort includes 278,108 subjects resident at the time of the accident or immigrating/born in the 10 years thereafter in three contaminated zones with decreasing TCDD soil levels (zone A, very high; zone B, high; zone R, low) and in a reference territory comprising surrounding, noncontaminated municipalities. Vital status and cause-of-death ascertainment were 99% complete. Adjusted rate ratios and 95% confidence intervals were calculated by using Poisson regression. Results confirmed previous findings of excesses of lymphatic and hematopoietic tissue neoplasms in zones A (six deaths; rate ratio = 2.23, 95% confidence interval: 1.00, 4.97) and B (28 deaths; rate ratio = 1.59, 95% confidence interval: 1.09, 2.33). These zones also showed increased mortality from circulatory diseases in the first years after the accident, from chronic obstructive pulmonary disease, and from diabetes mellitus among females. A toxic and carcinogenic risk to humans after high TCDD exposure is supported by the results of this study.