Science, People, and The Environment Anthony O. Oloni, MD, MPH, CPHI Environmental Science The systematic, scientific study of our environment as well as our role in it. The study of ecology: The branch of biology concerned with the relations between organisms and their environment Environmental Science Environmental science is the science of the interactions between the physical, chemical, and biological components of the environment, including their effects on all types of organisms but more often refers to human impact on the environment. Ecosystem http://www.wellersponds.com/EcoSystem.htm Environmental sustainability is an important concern of environmental science. Why? Examples of environmental sustainability! Environmental Sustainability! So, what is environmental sustainability? Environmental sustainability Long-term maintenance of ecosystem components and functions for future generations. The assessment that a projects outputs can be produced without permanent and unacceptable change in the natural environment on which it and other economic activities depend, over the life of the project. What is environmental Sustainability? Meeting the needs of the present without compromising the ability of future generations to meet their needs. e.g. Keeping population densities below the carrying capacity of a region, facilitating the renewal of renewable resources, conserving and establishing priorities for the use of nonrenewable resources Keeping environmental impact below the level required to allow affected systems to recover and continue to evolve Environmental Health Risk Assessment 1. As characterized by the WHO Identify of the environmental hazard Hazard and the effects of the hazard Dose-Response Assessment Relationship between the dose and health effect in humans Environmental Risk Assessment Exposure Assessment What exposures are currently anticipated under different conditions. Risk Characterization Estimation of the incidence of the adverse effect in the given population Environmental Risk Assessment Risk Management (Risk Control) Development, evaluation and implementation of regulatory options aimed at risk reduction and control Scientific Method The scientific method is the process by which scientists, collectively and over time, endeavor to construct an accurate (that is, reliable, consistent and non-arbitrary) representation of the world. Scientific Method The step by step process by which scientists investigate hypotheses using experiments. Is the testing of scientific principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of hypotheses Scientific Method Hypothesis: A proposal intended to explain certain presumed facts or observations A tentative theory about the natural world A concept that is not yet verified but that if true would explain certain facts or phenomena A scientific hypothesis that survives experimental testing becomes a scientific theory"; "he proposed a fresh theory of alkalis that later was accepted in chemical practices" Very educated guess: a message expressing an opinion based on incomplete evidence The scientific method steps Hypothesis A proposal intended to explain certain facts or observations A tentative theory about the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena; “A scientific hypothesis that survives experimental testing becomes a scientific theory"; "he proposed a fresh theory of alkalis that later was accepted in chemical practices" Scientific Method A process that is the basis for scientific inquiry. The scientific method follows a series of steps: (1) Identify a problem you would like to solve (i.e. does water increase its temperature when turning into steam?) (2) Formulate a hypothesis (3) Test the hypothesis (4) Collect and analyze the data (5) Make conclusions. The scientific method steps Observation We spend our lifetimes being observers. However, most of these observations are different from the ones which characterize scientific research. One of the early challenges in learning to be a psychologist is to distinguish between the casual observations you make as part of your everyday experience and the observations which can supply good behavioral data for a research project. The scientific method steps Data Collection The process of gathering and measuring information on variables of interest in an established systematic fashion that enables one to answer stated research questions, test hypotheses, and evaluate outcomes. The scientific method steps Analysis An investigation of the component parts of a whole and their relations in making up the whole. The process of explaining an entity or idea by examining it in terms of its various parts (e.g., a statistical technique for defining and segregating the causes of variability affecting a set of observations). The scientific method steps Conclusion A position or opinion or judgment reached after consideration; "a decision unfavorable to the opposition"; "his conclusion took the evidence into account"; "satisfied with the panel's determination" Scientific Method (1) (2) The procedure scientists follow to understand the natural world: The observation of phenomena or the results of experiments; The formulation of hypotheses that describe these phenomena and that are consistent with the body of knowledge available; Scientific Method (3) The testing of these hypotheses by noting whether or not they adequately predict and describe new phenomena or the results of new experiments; (4) The modification or rejection of hypotheses that are not confirmed by observations The scientific method steps Experiment the act of conducting a controlled test or investigation a venture at something new or different; "as an experiment he decided to grow a beard" Scientific Method Deductive Reasoning. Reasoning based on facts. Combined with empiricism to create scientific method. Drawing conclusions from observations of the natural world by means of logical reasoning. Deductive Reasoning Examples of deductive reasoning may be both subtle and time-saving. For example, Be careful of that wasp: it might sting. is based on the logic that wasps as a class have stingers; therefore each individual wasp will have a stinger. This conclusion is freeing in that we do not have to examine each and every wasp we ever encounter to ascertain what characteristics it may have. Because of the validity of deductive reasoning, we may make an assumption that is both useful and efficient. Deductive reasoning Deductive reasoning is the kind of reasoning in which the conclusion is necessitated by, or reached from, previously known facts (the premises). If the premises are true, the conclusion must be true. This is distinguished from adductive and inductive reasoning, where the premises may predict a high probability of the conclusion, but do not ensure that the conclusion is true. Deductive reasoning may also be defined as inference in which the conclusion is of no greater generality than the premises or inference in which the conclusion is just as certain as the premises. Deductive reasoning Deductive reasoning, or deduction, starts with a general case and deduces specific instances. Deduction is used by scientists who take a general scientific law and apply it to a certain case. Sherlock Holmes used deduction when he took some general indicators and deduced the specific details of a rather knotty case. Deductive Reasoning Deductive Reasoning is the process of reasoning from general principles to other general principles or specific examples. For example, a reasoner, knowing that all crows are black (a general fact about crows) can conclude that my pet crow (a specific example) is black. Similarly, the same reasoner, knowing that crows are birds, can conclude that some birds are black (another general principle regarding birds). Deductive Reasoning Much of the study of formal logic has involved mechanistic or algorithmic methods both for the representation of these general principles and for methods of making inferences from these principles that are guaranteed to be correct. When properly performed, deductive logic is sound, which is to say that if the premises of the argument are true, the conclusion is guaranteed to be true (or alternatively, if the conclusion is false, at least one of the premises must have been false; if my pet is white, then either I am mistaken in thinking it to be a crow, or not all crows are white). It should be noted that deductive reasoning can never generate "new" truths, therefore all genuine experimentation or empirical research will of necessity involve elements of inductive reasoning. Inductive Reasoning The process of thinking in which a conclusion is made based on observation Drawing a general conclusion based on a limited set of observations. Inductive Reasoning Inductive Reasoning is used when a sequence of individual pieces of information is generalized into a conclusion that relates to those pieces of information (e.g. After several cakes baked in the same cake pan came out burned, Carl concluded that if he bakes a cake in that particular cake pan it will probably come out burned). On the THEA test, an inductive reasoning question will take the form of a sequence of numbers or figures that exhibit a trend (increasing, decreasing, alternating, or a combination of these). By recognizing the trend, you must draw a conclusion about the next (or missing) number or figure in the sequence. Inductive reasoning Induction or inductive reasoning, sometimes called inductive logic, is the process of reasoning in which the premises of an argument are believed to support the conclusion but do not ensure it. It is used to ascribe properties or relations to types based on tokens (i.e., on one or a small number of observations or experiences); or to formulate laws based on limited observations of recurring phenomenal patterns. Induction "Induction is a major kind of reasoning process in which a conclusion is drawn from particular cases. It is usually contrasted with deduction, the reasoning process in which the conclusion logically follows from the premises, and in which the conclusion has to be true if the premises are true. In inductive reasoning, on the contrary, there is no logical movement from premises to conclusion. The premises constitute good reasons for accepting the conclusion. The premises in inductive reasoning are usually based on facts or observations. Induction There is always a possibility, though, that the premises may be true while the conclusion is false, since there is not necessarily a logical relationship between premises and conclusion." From: Grolier's 1994 Multimedia Encyclopedia Inductive reasoning is used when generating hypotheses, formulating theories and discovering relationships, and is essential for scientific discovery. Summary Inductive reasoning: (1) Conclusion based on several past observations (2) Conclusion is probably true, but not necessarily true Deductive Reasoning: (1) Conclusion based on accepted statements (definitions, postulates, previous theorems, corollaries, and given information) (2) Conclusion must be true if hypotheses are true Marginal Cost of Pollution A marginal cost is the additional cost associated with one more unit of something. Two examples of marginal costs associated with pollution are the effects of pollution on human health and on organisms in the natural environment.