Health Risk Assessment After Decontamination of the Beaches Polluted by the Wrecked ERIKA Tanker

Following the wreck of the oil tanker ERIKA off the north-west coast of France in December 1999, cleaning up of the beaches involved considerable work, which in any case could not be perfect. This raised the question of the short- and long-term health risks for the future bathers related to the toxicity of the remaining oil polycyclic aromatic hydrocarbons (PAHs). This risk assessment study was conducted to help health authorities plan risk management policies and inform the public. Thirty-six beaches were selected, representing a sample of the most frequently encountered topographic and beach usage situations; seven "control" beaches, unspoiled by ERIKA, were also investigated. Samples of water and sand were taken from each site, as well as from the surface of rocks. The 16 PAHs selected by the U.S. EPA were quantified in each environment. Several scenarios of exposure were contemplated: (1) a child between 2 and 4 years accidentally ingesting a small ball of fuel, (2) a child daily exposed throughout his holiday-time stay, (3) an adult (including a pregnant woman) spending his/her holidays on the coast, (4) an adult working on the beach, (5) and an adult practicing water sports. Among the available and significant toxicological values, the most conservative ones were selected for computing risks. The sand and water, after decontamination, were slightly polluted (respectively, 7.8 microg/kg and 23.3 ng/l of total 16 PAHs), with values similar to those found in the control beaches. By contrast, the rocky areas in some places were still highly polluted (up to 23 mg/kg on the surface layer). No lethal risk was found for a young child who had accidentally ingested a small ball of fuel. The life-long excess risks for skin cancer and for all other cancers were about 10-5 in scenarios including contact with the polluted rocks. In all other cases, excess risks were considerably lower. The hazard quotient for teratogenic effects was very small, except in scenarios where pregnant women would walk among rocks containing high pollution levels. In conclusion, exposure was mainly associated with polluted water among children, and with spoiled rocks for adults. Despite uncertainties, mainly dealing with the prediction of long-term risks following a short-term exposure, this study showed that beaches where pollution was no longer visible after decontamination did not entail any significant health risks and could be opened to the public.     

Integrated enterprise modelling: A method for the management of change

'The capability to adjust to new conditions quickly has developed into a decisive competitive advantage. You cannot waste any time if you want to be successful.' (Emeritus Professor Dr h. c. mult. Changing conditions in the market place issue new challenges to small- and medium-sized enterprises. Organization and qualification of employees have to be adjusted to the modified situation. If the only steady factor is change, the management of change is going to be the outstanding role of the leader. The successful structuring of change processes requires powerful methods and tools: to make business processes transparent and lean; to find a common 'corporate language' based upon customers benefits and shareholders value; Dr-Ing. G. Spur) to bring together process know-how in a central information base. This contribution summarizes the experiences from several projects. We will show how the synchronization of necessary reengineering measures makes corporate knowledge active, e.g. to improve the shareholders value, reduce investment costs, and shorten the duration of projects. As successful examples two medium-sized companies are described.     

Cause-of-Death Contributions to Educational Inequalities in Mortality in Austria between 1981/1982 and 1991/1992

This article uses census records and deaths records to analyze trends in educational inequalities in mortality for Austrian women and men aged 35–64 years between 1981/1982 and 1991/1992. We find an increasing gradient in mortality by education for circulatory diseases and especially ischaemic heart disease. Respiratory diseases and, in addition for women, cancers showed the opposite trend. Using decomposition analysis, we give evidence that in many cases changes in the age-structure within the 10-year interval had a bigger effect than direct improvements in mortality on the analyzed subpopulations.     

Does work during childhood affect the health of Guatemalan adults?

The diversity of potential relationships between child labor and health makes the empirical disentanglement of the causal relationship a difficult exercise. This paper examines the long run impact of child labour on health by controlling for unobserved household specific characteristics. In order to control for the unobserved households specific effect, we estimate a conditional fixed effect model using data on siblings constructed from the Guatemalan National Survey of Living Condition. The estimation results reinforce the conventional wisdom that child labor is harmful for health in the long run. The results can be interpreted as a lower bound of the true impact since healthier children are most likely to offer themselves for employment and to be appointed. The views expressed in this paper are those of the authors and do not necessarily represent those of IMF and IMF policy.     

Why is Six Sigma so successful?

There can be little doubt that Motorola, General Electric, Black and Decker, Allied Signal (now Honeywell), ABB and Bombardier, have achieved impressive business performance in recent years. Their annual reports document this success. Furthermore, in several cases, the Annual Report clearly attributes this success to having followed a Six Sigma strategy. Not surprisingly, many other companies wish to learn what Six Sigma can do for them, and their first question is 'What exactly is Six Sigma?'. Unfortunately it is rather difficult, if not impossible, to define Six Sigma in one or two sentences. This paper identifies the essential elements of Six Sigma. Some are obvious, such as the extensive use of statistical techniques by employees known as Blackbelts. However, other more subtle, but very important, features of Six Sigma are concealed within the business culture of these successful companies. It is clear to those who have participated in this success, that any company embarking on Six Sigma will not succeed if it focuses on statistics whilst failing to develop a supporting culture.     

Markov Chain Monte Carlo in small worlds

As the number of applications for Markov Chain Monte Carlo (MCMC) grows, the power of these methods as well as their shortcomings become more apparent. While MCMC yields an almost automatic way to sample a space according to some distribution, its implementations often fall short of this task as they may lead to chains which converge too slowly or get trapped within one mode of a multi-modal space. Moreover, it may be difficult to determine if a chain is only sampling a certain area of the space or if it has indeed reached stationarity. In this paper, we show how a simple modification of the proposal mechanism results in faster convergence of the chain and helps to circumvent the problems described above. This mechanism, which is based on an idea from the field of “small-world” networks, amounts to adding occasional “wild” proposals to any local proposal scheme. We demonstrate through both theory and extensive simulations, that these new proposal distributions can greatly outperform the traditional local proposals when it comes to exploring complex heterogenous spaces and multi-modal distributions. Our method can easily be applied to most, if not all, problems involving MCMC and unlike many other remedies which improve the performance of MCMC it preserves the simplicity of the underlying algorithm.