Fertilizers, water quality, and human health

Predicting cytotoxicity of complex mixtures in high cancer incidence regions of the Huai River Basin based on GC-MS spectrum with partial least squares regression

Complex mixture exposures, such as those associated with water sources, are an important issue in health risk assessment. This study assessed the cytotoxicity of chemical mixtures extracted from water sources in regions of the Huai River Basin with high cancer incidences and built statistical models of cytotoxicity based on pollution profiles that were measured with gas chromatography-mass spectrometry (GC-MS). Both surface and ground waters were collected from rural water sources of Shenqiu County, Henan Province of China from 2008 to 2011 and extracted with XAD-2 resigns. Cytotoxicity was evaluated with Chinese hamster ovary K1 (CHO-K1) cells and compared against the pollution profiles of the extracts. IC50 of water samples ranged from 0.023 to 0.338L-eq/mL. The pollutants in waters determined by GC-MS are complex and some of the compounds that contributed to cytotoxicity lack toxicity data. A partial least squares (PLS) regression model of cytotoxicity was built based on linear aggregation of predictor variables (i.e., peaks for single compounds in the gas chromatograms). The PLS model contains 2 PLS factors extracted from 141 variables. The model was validated internally with training data permutation and externally with a test sample. The model explained 92% of the cytotoxicity in the training samples and 40% in the test sample. This approach provides a general, rapid method for relating water toxicity to GC-MS chromatograms and for predicting the compounds that contribute most to toxicity.

The social determinants of cancer: a challenge for transdisciplinary science

To make further significant advances in cancer control research, a transdisciplinary science approach is needed that integrates the study of the biological nature of cancer and its clinical applications with the behavioral and social influences on cancer. More-effective interventions to reduce the burden of cancer can be developed and implemented by the adoption of a transdisciplinary research framework that takes into account the social determinants of cancer and seeks to discover interactions among social, environmental, behavioral, and biological factors in cancer etiology. This paper addresses two critical issues in the science of team science: (1) a cross-disciplinary, multilevel framework for organizing future research, and (2) a perspective that could aid in the translation and dissemination of cancer research findings in health care and public health practice. This conceptual framework is designed to encourage transdisciplinary research that will integrate social determinants into cancer research. The authors' goal is to promote a more complete understanding of the causes of cancer that will lead to the improved translation and implementation of the results of research.

Integrating nutrition with ecology: balancing the health of humans and biosphere

Objective

To show that current rates of global population growth, production and consumption of food, and use of living and physical resources, are evidently not sustainable. To consider ways in which nutrition and allied sciences can respond to this great challenge of the twenty-first century.

Method

Past, current and future projected trends in production and consumption patterns are examined. These show that overall present and projected patterns cannot be sustained; and also show increasing unacceptable inequity between and within rich and poor regions and countries.

Discussion

Nutrition science classically focuses on nutrients in relation to human physiology, metabolism, growth, health and disease. The social and environmental conditions of the modern, interconnected, market-oriented world, and the consequences for food production and consumption, are extending the research and policy agenda with which nutrition science must now urgently engage. Historically, much attention has been paid to eliminating nutritional deficiency states, and this remains an important task. In modern urban populations ‘malnutrition’ encompasses new forms of dietary imbalance, especially excesses of certain nutrients. These contribute to various non-communicable diseases and, particularly, to overweight/obesity and its attendant metabolic derangements and disease risks. As a mass phenomenon the current surge in obesity has no historical precedent. The escalating impact of humankind on the natural environment, with its ramifications for present and future food production, is also unprecedented.

Conclusion

The essential challenge for nutrition science is to develop new understanding and strategies to enable a balance between promoting, equitably, the health of humans while sustaining the long-term health of the biosphere. Extension of nutrition science and food policy to meet those goals will be aided by understanding better how dietary conditions shaped the biological evolution of humankind. The fundamental long-term task is to integrate human health with the health of the biosphere.