**1. Introduction**

According to 2017 estimates of accidents and work-related diseases and deaths report released by the International Labor Organization (ILO), each year 2.78 million workers die from occupational accidents of which 2.4 million are disease related, approximately 86.3% of the total estimated deaths. The work-related mortality accounted for 5% of the global total deaths (based on the Global Burden of Disease Study 2015) and fatal accidents accounted for the remaining 13.7% [1]. Likewise, for 2017, BLS reported 282,750 MSD cases resulting in days away from work in the private sector, a continued decrease from the previous year (285,950) [2]. Work-related musculoskeletal disorders (WMSDs) accounted for 31.2% of all injuries and illnesses involving days away from work and remain the largest source of injury and illness cases [2]. Therefore, work-related issues have led to the explosion of research on safety and health for workers in the ergonomics and human factors, medical, psychological, engineering, science, nursing, and environmental literature for over two decades. The health and safety hazards address both acute and chronic hazards workers are exposed to at workplaces daily. These days health hazards at workplaces attract more attention because of the potential harm associated with the employee's exposure and the monetary cost attributed to a single cause. Thus, everyone wants a safe and healthy workplace for proper operation and productivity of the employees. Therefore, health and safety at work is aimed at creating conditions, capabilities, and habits that enable the worker and the organization to operate efficiently and in a way that avoids events that could cause them harm [3].

To reduce the rate of accidents reported every year at work, the United State (US) enacted a law to oversee the safety and health of workers at various workplaces in 1970, known as Occupational Safety and Health Act (OSHA). The act was enacted purposely to ensure that employers provide safe working environment for all employees. The importance of human safety and good health cannot be overemphasized or overestimated. Before the existence of OSHA, the National Environmental Protection Policy Act of 1969 became the basis of the environmental protection in the US. This chapter provides the overview of the book on safety and health for workers from research and practical application perspectives.

Everyone is exposed to at least one hazard daily and constantly interacts with different hazards on daily basis. The hazards concern with safety and health hazards, include biological, botanical, mechanical, chemical, physical, etc. Human beings cannot escape inhalation, egestion, injection, and absorption processes, even if they refuse to engage in daily work activities. Thus, it is imperative to study in depth the processes and the methods to control and manage the everyday hazards

humans are constantly exposed to. Furthermore, to complicate issues, human typically operates under different constraints including inability to survive without interaction with one another, environments, materials, and equipment on daily basis to function as human. Given these constraints, human beings are forced to maintain good health while performing their daily tasks by using good judgment during decision-making. Exposure to hazardous materials is inevitable but human errors, time of exposure, concentration, and the dose of the hazardous materials determine the effect on safety and health of the workers. To reduce the likelihood of making errors, human beings must first understand the theory behind each operating process of any activity before engaging in it. Therefore, identification and recognition of hazards relating to the theory and the applications of the principles of handling the hazards are the significant ways for protecting human safety and health at work.

In a cafeteria in the northwest region of United State (US), a teenager rushed out from a restroom and everyone seated immediately perceived unpleasant odor. At once, everyone choruses what is this? The sister of the teenager boy asked her brother "did you wash your hands? The boy responded oh NO, I forgot." Immediately, debate on why and how started in the room that inspired other customers to join the discussion.

Likewise, Wickens et al. [4] document a situation in the Midwestern factory in US on an assembly-line worker. In the scenario, the assembly-line worker had to reach to an awkward location and position a heavy component for assembly. Toward the end of a shift, after grabbing the component, he felt a twinge of pain in his lower back. A trip to the doctor revealed that the worker had suffered a ruptured disc, and he missed several days of work. He filed a lawsuit against the company requiring physical action that endangered the lower back.

A young lady who graduated with GPA of 4.0 from one of the ivy league Universities in US, pick up a supervisory role position in a multi-million construction company and having worked for 5 years in this position, she realized that her health has been deteriorated. She visited the doctor and discovered she suffered from cardiovascular damage, gastrointestinal problems that has led as ulcers and irritable bowel syndrome, and decreased fertility. She requested for damage compensation from the company.

This book is designed to address the theory of safety and health for workers and the practical applications to solving issues associated with hand hygiene, social support, ergonomics-spine deformity, workplace conditions, health equality, etc. at workplaces.
