Poisoning through environmental chemicals has been with humans for a long time: from lead poisoning in ancient Rome over workplace exposure to mercury in 19th century Britain to multiple tragedies due to environmental poising in the 20th century. Most recently, on July 16th 2013, 23 Indian schoolchildren died in the Gandaman village after eating a contaminated school lunch. The deaths were more than likely caused by an acute intoxication from the pesticide monocrotophos.
In an editorial to be published in Archives of Toxicology, appearing online at http://link.springer.com/journal/204 in mid-August and in print around September 15th, toxicology and stem cell scientist members of an EUFP7 funded consortium to develop alternative human stem cell based models for toxicology (ESNATS) comment on Gandaman village tragedy. Monocrotophos is a chemical belonging to the group of organophosphates. The pesticide is insecticidal, but also highly toxic to other animals, including birds and mammals.
Its use has therefore been banned in many Western countries. It is however still used in South America, Africa and Asia, including India. The apparently high efficacy of crop protection by monocrotophos probably explains the continued use of this dangerous pesticide in certain countries. To put things in context, malnutrition in India is very common. According to UNICEF, one in every three malnourished children in the world lives in India (UNICEF website). India desperately needs food and its poor depend heavily on affordable mass production, which includes the use of cheap and potentially very toxic pesticides. Such pesticides will therefore stay around for the foreseeable future.
Following the Gandaman incident, the superintendent of the Medical College hospital in Patna (a city close to Gandaman) downplayed the effects of acute poisoning , saying that children who survived the acute intoxication will have “no remnant effects on them” (Huffington Post 2013/07/18). Professor of Medicine Karl-Heinz Krause, Geneva/Switzerland says: “This statement is misleading as long-term consequences of organophosphates poisoning include organophosphate-induced delayed polyneuropathy and chronic organophosphate-induced neuropsychiatric disorder. Such long term toxicity of organophosphates may even occur in the absence of documented acute intoxication and such cases might be much more frequent than fatal acute intoxications. In addition, low-level prenatal exposure is associated with reduced IQ scores and deficits in working memory.”
To the best of present medical knowledge, monocrotophos is not devoid of this long-term organophosphate toxicity, but reports are more sketchy than for other pesticides. Toxicologists Professor Jan Hengstler and Dr Christoph van Thriel, Dortmund/Germany say: “When it comes to protecting the legal rights of victims and their families, our present medical knowledge is not good enough. Toxicity mechanisms need to be demonstrated and unequivocal cause/consequence chains need to be established.”
“Understanding the mechanisms of organophosphate toxicity is critical in two respects. First, therapeutic strategies for patients exposed to these toxics can be developed. Second, such studies should allow legislators to create legal frameworks that encourage the use of pesticides with the least unfavorable toxicology profile.”, says Professor Marcel Leist, Konstanz/Germany.
It is crucial to identify low cost pesticides with as little long-term toxicity as possible. To achieve this goal, collaboration between clinical, epidemiological, and experimental toxicologists is necessary. Toxicologists need to study the impact of toxic compounds in physiologically relevant model systems, rather than using only immortalized cell lines, and to study the impact of toxics in human model systems, instead of relying exclusively on results obtained in other species.
Dr. Paul de Sousa, University of Edinburgh/UK explains: “The advent of pluripotent stem cells (PSC) provides significant opportunities for such studies. The impact of toxics on virtually all types of cell types can be studied without recourse to immortalized cell lines.” The European consortium ESNATS (Embryonic Stem cell-based Novel Alternative Testing Strategies), a partnership of scientists from 29 organisations from all over Europe and Israel receives funding from the European Commission’s 7th Framework Programme for Research and Development to develop pluripotent stem cell-based toxicity tests.
First results demonstrate that such test systems may indeed become powerful tools. The use of PSC technology is threefold. It allows for ethnic diversity of humans to be included in analysis, for toxics to be tested on tissues rather than on isolated cells, and for mice to be generated with humanized organs, advancing the level of complexity required for translatable experimental toxicology research.
Contacts:Prof. Karl-Heinz Krause, Dept. of Pathology and Immunology, Geneva Medical Faculty (Switzerland)
Prof. Jan G. Hengstler | idw
Inflammation Triggers Unsustainable Immune Response to Chronic Viral Infection
24.10.2016 | Universität Basel
Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering