# Environmental Health Engineering Theory and Practice/Introduction
## Introduction

The title of this wikibook, Environmental Health Engineering Theory and Practice, was selected with great intention to serve as the organizing principle for the text. For example, environmental describes where we focus our interest. The environment is the space around or between objects. It can be natural or it can be human-made. The environment provides life support - air to breathe, water to drink, and food to eat. And the environment can be degraded through its use (i.e., pollution). Similarly, health describes what is the focus of our interest. Health is not only the absence of disease, but it is also much more the promotion of wellness. If we presume that the natural state of humanity is healthy, then the purpose of environmental health engineering becomes to return the human to health through manipulation of the environment. And finally, engineering is the how of our focus. Engineers design and deploy technology to meet the needs of humanity - from the bridge over the river to the mobile communication device that connects one human to all of humanity. Environmental health engineering is a noble profession, which traces it origins to the earliest excavations of human settlements - to garbage mounds with broken pottery and the earliest toilets.
Theory and Practice references the twin pillars that support the profession of environmental health engineering. Engineers learn through experience; we are a profession of tinkers who constantly attempt to improve the world around us through the use of technology. Mathematics and science are two of the tools of engineering; we use math to describe our work, and we use the knowledge of science to help inform our best engineering guesses (i.e., guesstimates. Because engineering is constantly striving to create something new, it may not be possible to predict the outcome from an application of technology (i.e., we often lack an understanding of failure). Therefore, engineers use the scientific method in a poor imitation of the scientist. None the less, the engineer has an obligation to understand the current theoretical frameworks developed by scientists, and to use these theories as first principles for our work.

## Describing the Sections of this Wikibook

This wikibook begins with an introduction to the theory of environmental health engineering. This theory is grounded in the modified toxicological paradigm first developed and then further refined by healthcare professionals at The Johns Hopkins University. In brief, the environment and disease are connected by the human through exposure and manifestation of illness. Important concepts in the toxicological paradigm include the role of genetics and susceptibility, and details include vectors and routes of exposure. From there, this wikibook will explore both core and additional practices of environmental health engineering as described by the National Environmental Health Association - a professional body that administers the Registered Sanitarian Exam as part of a pathway towards professional recognition as a practitioner of environmental health. Some of the core areas include disaster response as well as protecting air, water, and food. Some of the additional areas include housing, noise, and pools as well as regulatory frameworks.
As with other healthcare professions, environmental health engineering is an emerging field of practice, with new discoveries uncovered everyday. To capture the latest details of these areas of emerging interest, a section entitled, "Emerging Areas" has been included in the Table of Contents. And because environmental health engineering is an area of professional practice within healthcare, it is important to learn by doing - or, at least to learn by reading, discussing, and reflecting on case studies, which are in-depth descriptions of practical challenges faced by environmental health engineers. Each case study is identified by one or more relevant portions of theory and one or more areas of practice, and each case study includes references to additional resources as well as guiding questions, which may be used to facilitate both face-to-face discussion as well as reflection via a discussion board or other form of written communication.

## Encouraging Readers to be Authors

As a wikibook, Environmental Health Engineering Theory and Practice is meant to be alive and interactive. Where you find confusion is the text, take time to fix it. Where you have a serious disagreement with the text, take time to comment on the talk page. And when you have new areas of emerging interest or case studies to offer, add them! Authoring, editing, and updating a wikibook is the responsibility of everyone who finds value in these pages. Yes, partake in consuming the knowledge provided, but also take professional responsibility for improving our profession through active stewardship of this wikibook. YOUR participation is vital!

## Useful Off-site Resources

* Biological markers in environmental health research. Committee on Biological Markers of the National Research Council, (1987)
* A niche for infectious disease in environmental health: rethinking the toxicological paradigm, (2010)
* NEHA: National Environmental Health Association