Environmental health can be defined as the discipline and practice of preventing human injuries, illnesses and diseases by promoting well-being, recognising and assessing environmental sources of hazardous agents and reducing exposures that may adversely affect human health. It involves a focus on health protection by monitoring, regulating and eliminating physical, chemical, and biological hazards in all parts of the physical environment such as air, water, soil, food, and other environmental media or settings.Environmental Health is that branch of public health that promotes healthy and safe relationships between people and their environment. As one of the major arms of a complete public health system, environmental health involves advocating, implementing and evaluating policies and programs to reduce health hazards in the environment, especially during and after emergencies.

Emergencies and disasters, including natural disasters, chemical or radiological accidents and complex conflicts are inevitable.Hence, it remains the responsibility of governments and international organizations such as World Health Organization (WHO) to pre-empt and effectively manage these disasters when they occur. The risk factors for disease outbreaks following emergencies or disasters result mainly due to environmental risk factors and population displacement. These factors interact to influence the risk of diseases and death in the affected population, they include availability and accessibility of safe water, the level of crowding and sanitary conditions, existing health condition of the population and the availability of healthcare services (Watson, J. T., et. Al. (2007).

In a study that reviewed potential infectious diseases resulting from the after-effects of natural disasters between 2000 and 2011,researchers found that those disasters including floods, tsunamis, earthquakes, hurricanes, typhoons and tornadoes were associated with infectious diseases such as diarrhea, acute respiratory infections, malaria, leptospirosis, measles, typhoid fever, meningitis, tetanus, dengue fever, viral hepatitis and cutaneous mucormycosis (Kouadio, I. K., et. al (2012).

To completely prevent these emergencies may be impossible because they’re natural, however, handling and managing them can be better. It’s also possible to reduce the probability of their occurrence as well as the resulting consequences and the community’s vulnerabilityif they occur, through vulnerability assessment and other technical means.To reduce the chances of these disasters happening as well as their impact on health and lives, proper planning (emergency preparedness) and actions must be in effect. These plans are usually more cost-effective compared to the costs of dealing with the disasters. Some activities recommended by WHO to reduce the probability and impact of emergencies and disasters include raising awareness, and emergencies, sustainable management of land and infrastructure,effective warning systems, development of relevant national policies, construction of earthquake-resistant buildings, providing water supplies and sanitation systems in earthquake-prone regions and learning from experiences of previous disasters. These activities all require the participation of federal, state and local governments

Given the many differences between developed and developing countries, there are variations in how global health is accepted and practiced in these countries. Developed countries are sovereign states with well urbanized economies and advanced industrial, technical and scientific infrastructure compared to developing or less developed nations. Most commonly, the criteria for evaluating or assessing the degree of economic development include gross domestic product (GDP), gross national product (GNP), the per capita income, level of industrialization, amount of widespread infrastructure and general standard of living. Furthermore, global health practice and health development may be assessed by quality of life, morbidity and mortality rates, research output, amount and availability of funding, life expectancy. Therefore, it is not always black and white which countries should be categorized as developed- and in what areas, and which should be termed developing.

In addition to the differences in the economies and health systems of developed and developing countries, there are also differences in the disease burdens in these countries. The disease burdens in a country- to a large extent, determine its health resources, promotions and global health practice. Developed countries are burdened mostly by chronic diseases such as cancer, diabetes, heart disease and AIDs while developing countries are burdened by infectious diseases such as malaria, diarrhea, pneumonia and flu. Most recently however, developing countries face a double burden of disease due to the consistent adoption of western lifestyle and culture. Infectious diseases in developing countries account for more than 20% of the disease burden world-wide, yet attract less than 1% of the total public and private funds dedicated to health research. Despite bearing 90% of the global disease burden, developing countries receive only 10% of all health research funding used to address these diseases. As a consequence, health care and global health practices are often poorer in developing nations.

It is very important to strengthen healthcare and research capacity in developing countries through national and international funding and collaboration. Currently, several non-profit organizations and governmental bodies, with the help of World Health Organization, Canadian Coalition for Global Health and Commission on Health Research for Development, are making efforts to address this global health research imbalance, commonly known as the 10/90 gap. The imbalance in global health funding, standard of living, GDP and other markers of development between developed and developing countries essentially affect the quality of health care and services in these countries. These in turn affect the practice and progress of global health. Global health, typically defined as the collaborative, multinational, research and action for health promotion, is founded on national public health efforts and organizations. It can be equated principally with individual based and population-wide interventions consisting of strategies for health promotion and improvement, and across all sectors, not just health. Developed countries are pioneers in health research, universal health care and progressive health promotion initiatives mostly because of the amount of funding available for health and also because of their experience and culture.

Despite differences in global health practices, health inequalities exist between population groups in all countries including developed and developing countries. However, the causes of inequalities in these countries may differ significantly. These differences are visible across several groups of social stratification including socioeconomic, political and ethnic.

Victimization refers to the unjustifiable targeting of an individual or a group for subjection to crime, exploitation, unfair treatment, or other wrong. It is the process of hurting someone or a group of people (victims) by perpetuating or committing a crime against them. Victimization can take either psychological forms through as bullying, verbal abuse or physical forms through sexual abuse, murder, torture, burglary robbery and assault. The rate of victimization may be influenced by age, gender, social group and location.  Although anyone can be a victim, specific groups such as children, seniors and disabled individuals may be more susceptible to certain types of victimization. For example, bullying or peer victimization is most commonly found in children and adolescents. Victimization is criminal act which is a frightening, unsettling, unexpected and largely unpreventable experience. Sometimes, people are victimized by people who are known to them, not strangers. A peer reviewed study published in PUBMED showed that specific types of victimization such as physical bullying and sibling assaults, were highest prior to adolescence and then declined afterwards. Other types of victimization were influenced by gender- for instance, peer assaults increased in adolescence for boys but not for girls. Child maltreatment and sexual victimization increased in adolescence for girls but not for boys. Symptoms of victimization may vary in several ways and are associated with the type of victimization as well as characteristics and experiences of the victim.

The impacts of victimization can be observed in four broad aspects of life including emotional, physical, psychological and financial aspects. Emotional impacts of victimization include feelings of shock, incredulity and denial. These reactions can last for as short as a few minutes or as long as a few years. Following these reactions are stronger and more aggressive feelings of anger, fear, frustration, confusion, guilt, shame, and grief.

Physical impacts of victimization begin from the moment the event is occurring or after the realization that the event has occurred. Victims are likely to have a number of physical experiences or changes which may include increased adrenalin in the body, increased heart rate, hyperventilation, profuse quivering, tearing, numbness, dryness of the mouth and enhancement of the sense organs. There are also physical injuries that result from crime and they can be classified as: minor, moderate and major injuries. Minor injuries include scratches; moderate injuries may include bruises while major injuries are broken bones and damage to internal organs. Some victims may experience long-term health-related side effects such as ongoing headaches, chronic pains, stomachaches, disability and depression.

Psychologically, common reactions to crime can include feeling helpless, paranoid and disorganized. These are closely followed by distressing thoughts about the event, nightmares, depression and a loss of confidence. Behavioral responses to these psychological effects include increased alcohol or substance abuse, fragmentation of social relationships and social withdrawal. The financial impact of victimization occurs in victims who lost money or possessions and have been financially injured. It also occurs when victims are unable to return to work or find a means of livelihood due to their injuries and experiences. Other ways that victimization can incur costs to victims include repairing or replacing possessions, higher insurance premiums, medical and burial expenses, court appearances and time off from work.

Victimization can be prevented by being aware of their one’s environment, making safety plans such as access to emergency and help hot lines and taking self-defense courses.

The term marginalization is a well recognized social factor and a determinant of health used across disciplines including health, education, sociology, psychology, law, public policy, politics and economics. Marginalization, also known as social exclusion, can be described as a situation whereby individuals or groups are systematically and structurally deprived or denied access to some rights, opportunities and resources that are normally available to other individuals or groups. According to World Health Organization, social exclusion is driven by dynamic processes that consist of unequal power relationships across the economic, political, social and cultural aspects of the society.  It occurs at different levels including individual, family, community, national and international levels. Marginalization may be based on factors such as race, age, gender, class, status, religious affiliation, disability, ethnic origin, educational status, prejudice, living standards, or appearance. It is visible in many aspects of the society including healthcare, housing, employment, civic engagement, democratic participation, and due process.

Marginalization is demonstrated through subtle or obvious actions including use of derogatory language, assuming people’s accomplishments are not based on merit, stereotyping, denying people academic or professional opportunities because of their identity, limiting access to certain resources based on membership in a particular group, disregarding people’s cultural or religious traditions and values.

Marginalization results in unequal access to, and use of resources, potentials and rights of people which leads to health inequalities. The consequences of marginalization and social exclusion are evident in societies, as affected individuals or communities are prevented from participating extensively in the economic, social, and political life of their respective societies. Several health problems, notably, mental health problems, can arise from social exclusion. Feelings associated with poor mental health such as low self-esteem, stress, rejection, loss of social connections, loneliness, hopelessness, isolation, resentment, decreased opportunities for engagement, boredom and stigma are experienced by marginalized people and groups. A study published on American Journal of Psychology found that individuals who were marginalized behaved more aggressively compared to those who were not. In the study, several experiments showed that people who were excluded were aggressive towards the people who excluded them and non-aggressive to people who did not exclude them. These responses were specific to social exclusion and when translated to the society implies that marginalization perpetuates division, hatred, paranoia, resentment, aggression and the likes.

Marginalization can be addressed if all individuals can speak up or act when any act of injustice, intolerance, or oppression is being carried out

As described by the World Health Organization (WHO), health financing involves the generation, allocation and use of financial resources in health systems. The aim of health financing is to make funding available, provide financial incentives to health service providers and ensure that all individuals- irrespective of wealth and social class, have access to effective public health and personal health care. Policies regarding health care financing are aimed towards universal health coverage especially relating to:

• Sources and ways to raise and pool together sufficient funds for health
• Means to overcome financial barriers that cause disparities in health care
• Ways to increase healthcare access as well as provide equitable and efficient variation of health services

Health financing ensures the provision of funds and resources needed for the operation of health systems. It is a major determinant of the performance of health systems, and can be assessed in terms of equity, efficiency, and health outcomes in a particular country or region. Directing public funds towards services that address the healthcare needs in a population is essential for a country to prosper health-wise, and attain universal health coverage (UHC) – the gold standard for health financing. UHC is a system of healthcare financing that ensures all populations and communities can access and use the health care services they need. These services may be preventive, curative, palliative or rehabilitative and should be efficient, economical, effective and of good quality. The current system of financing in health care- UHC is based on three major principles including:

• Equitable access to health services
• Standardized and excellent quality of health services
• Protection against financial-risk

UHC is rooted in the 1948 constitution of WHO which documented health as fundamental human right. Subsequently, the Alma Ata declaration emphasized the Health for All agenda in 1978. Health financing is crucial to both the quality and accessibility to healthcare. Although not fully implemented in many countries due to private out of pocket financing, UHC is the WHO recommended method of healthcare financing because of its benefits. Private financing and out of pocket payment perpetuates inequities in healthcare accessibility and use. Consequently, public funding aims to achieve UHC which seeks to eliminate these inequities by providing the same quality of care to all people across board- rich or the poor, in rural or urban communities. The future of health financing is tending towards UHC for most developed countries, although there is still some private funding. However, in undeveloped countries like Nigeria, where the government doesn’t care about citizens, private out of pocket funding is still foremost.

Globally, infectious diseases have remained the leading cause of death. Years ago, scientists assumed that the battle against these diseases was finally over; unbeknownst to them, this battle was far from being over. Events in the last few decades emphasize this persistence. New diseases such as AIDS, Legionnaire disease, and hanta-virus pulmonary syndrome have emerged while diseases that seemed eradicated such as malaria and tuberculosis are re-surging. The resurgence of previously conquered infections may be due to factors that include the characteristics of the pathogen and inefficient public health standards to guarantee their extinction.

Emerging infectious diseases (EID) are diseases whose incidence have increased in recent years, with the potential to continue increasing in the future. They usually have the following characteristics: have not or rarely occurred in human population before, occurred in the past and affected few people in secluded locations or have just been recently identified. On the other hand, re-emerging infectious diseases are diseases that caused national or global health problems in the past and were eradicated, but somehow have re-surfaced again to constitute outbreaks. Emerging and Re-emerging diseases go hand in hand- sometimes, infectious disease specialists classify the latter as a subcategory of the former. Reemerging infections account for about 12% of all human pathogens and may result from the following:

• Complacency, carelessness and lack of effective public health standards (Drug resistant tuberculosis, Poliomyelitis)
• Newly identified organism (Severe acute respiratory syndrome, HIV/AIDS)
• Evolution of a known strain (Influenza, Tuberculosis)
• Spread to a new population (West Nile fever)
• Spread to a region undergoing ecologic transformation (Lyme disease)
• Microbial adaption (Influenza A)
• Changing human susceptibility, demographics and trade (HIV, SARS)
• Climate and weather (West Nile Disease )
• Economic development and invention (Antibiotic resistant strains)
• Poverty and social inequality (Tuberculosis)
• Bioterrorism (2001 Anthrax attacks)
• Dam and irrigation system construction (Malaria and other mosquito borne diseases)
• Zoonotic encounters (HIV)

Notably, Tuberculosis for instance re-emerged due to the evolution of Mycobacterium Tuberculosis, the causative organism. This pathogen evolved and became resistant to the antibiotics it was once sensitive to. This occurs through mutation, genetic exchange or abuse of antibiotics.  Malaria has also become drug resistant and the vector, mosquito, has acquired resistance to pesticides. Furthermore, the resurgence of diseases such as diphtheria and whooping cough (pertussis) was due to inadequate vaccination which occurs when the proportion of immune individuals in a population falls below an expected threshold.

Despite the challenges of emerging and re-emerging infectious diseases, research shows that there is hope; noteworthy breakthroughs include:

• Increased vaccination
• Development of HIV protease-inhibitor drugs which when used in combination with other anti-HIV drugs, dramatically decreases deaths from AIDS
• Research on the ecology of disease organisms—their reservoirs, modes of transmission, and vectors, revealing preventive measures to interrupt disease cycle and prevent outbreaks.

Hearing loss is a major public health problem, affecting 360 million people worldwide. It is the third most common health problem in the United States (US) – with about 48 million Americans having lost some degree of hearing. It affects quality of life and relationships, and may result in depression, social isolation, unemployment, high blood pressure and increased risk of falls. Major factors that cause and facilitate hearing loss include aging, illness, genetics, medications and noise.

Statistically, humans begin to lose hearing from about 30 to 40 years. Age is the strongest predictor of hearing loss among adults aged 20 and above, with the greatest burden on people aged 60 and above. Age related hearing loss is called Presbycusis, and occurs gradually as individuals become older- one third of people aged 65-74 and about half of people aged 75 and above. This could be as a result of the fact that over the years, the ear’s efficiency to hear gradually wears out due to the following: changes in the structures of the inner ear, changes in blood flow to the ear, impairment in the nerves responsible for hearing, changes in the way that the brain processes speech and sound, damage to the tiny hairs in the ear responsible for transmitting sound to the brain, diabetes, poor circulation, exposure to loud noises, use of certain medications, family history and smoking. There is no cure for age-related hearing loss; however, doctors may recommend the following to improve hearing: hearing aids, assistive devices, such as telephone amplifiers, lessons in sign language or lip reading and cochlear implant. In addition to aging, noise is another factor that wears out hearing especially when it’s loud or constant. Some jobs such as Carpentry and Plumbing increase the risk of hearing loss since workers are exposed to dangerous noise levels daily- 44% of carpenters and 48% of plumbers report some hearing loss .

Based on which part of the auditory system is affected, there are 3 major types of hearing loss and they include sensorineural, conductive and mixed hearing loss. Sensorineural hearing loss occurs when the inner ear (cochlea) or hearing nerve in the brain is damaged. Some possible causes are aging, excessive exposure to loud noise, viral or bacterial infections, medications, ear tumor and other hereditary factors. Conductive hearing loss occurs when there is inefficient conduction of sound through the ear canal, ear drum or middle ear. Possible causes include ear infection, presence of fluid or foreign objects in the middle ear, scarring of the eardrum, build-up of wax, ossicles dislocation, otosclerosis and tumors. Finally, mixed hearing loss results from a combination of sensorineural and conductive hearing loss, affecting both the middle ear and inner ear. Hearing loss can also be classified based on the severity of the problem- four classes exist and they include: Mild hearing loss- where it’s hard to comprehend every word in a noisy background; Moderate hearing loss- where words have to be repeated before they’re comprehended; Severe hearing loss- where it becomes difficult and impossible to follow a conversation without a hearing aid and Profound hearing loss- where it’s impossible to hear people unless they shout.

Symptoms of hearing loss vary broadly depending on the type, cause and severity of the problem. In general, affected people may experience one or more of the following: difficulty understanding conversations, difficulty hearing without repetition, increased difficulty communicating in noisy environments and tinnitus, or ringing sounds in the ears. Hearing loss can be diagnosed by a series of tests such as initial examination using an otoscope, pure tone test, bone conduction test, speech test, tympanometry and audiogram. Given that most cases of hearing loss are untreatable, irreversible and can only be managed, it is best to prevent the problem. Recommended prevention methods include avoiding repetitive exposure to loud sounds and wearing ear protection when exposed to loud sounds.

Several factors pose threats to the health, well-being and safety of populations, as well as the economy of countries across the world. These factors include public health issues such as communicable or infectious diseases, bio-terrorism, natural disasters, man-made disasters, and non-communicable diseases.

The importance of global health protection and security has become more necessary given the advent of many epidemics and threats to global health security. The world today is synonymous to a global village, with high rates of mobility and connection through airplanes, speed boats and trains. Consequently, the impact and effect of diseases and other health problems can spread across wide geographical regions in a matter of hours. As the Center for Disease Control and Prevention (CDC) puts it, an outbreak anywhere, is indeed a threat everywhere. More so, there is need for protection against biological warfare (Bio-terrorism) which involves the use of biological weapons- toxins and infectious agents such as bacteria, viruses, and fungi, as an act of war to kill or debilitate humans, animals or plants.

The aim of global health protection and security is to remain one step ahead of potential outbreaks, and to be prepared to act quickly in the case of emergencies. This preparation involves having both the human and financial resources sufficient to handle any outbreak. Lack of emergency preparedness and weakness in the health system allows for diseases to thrive and spread, ultimately transforming local outbreaks into global epidemics. During an outbreak, time is of the essence, therefore it is essential to detect, prevent and rapid spread of diseases immediately. Early intervention and outbreak control prevents morbidity and mortality that can potentially overwhelm the health system and economy. Furthermore, outbreaks- like other accidents are unpredictable and can happen at any time with grave consequences. These consequences include the cost of controlling outbreaks, decrease in travel and tourism and instability of businesses, staggering economic growth, increase in the cost of health services and disruption in international trade. In the United States (US), The Commission on Global Health Risk Framework for the Future (CGHRFF) estimates a total cost of $6 trillion USD for global pandemics.

Different countries have different bodies responsible for global health protection and security. In the US, Division of Global Health Protection (DGHP) of the CDC is responsible for protecting citizens from public health problems in this regard. There is need for a worldwide effort through the Global Health Security Agenda, to strengthen every country’s capacity to prevent, detect, and respond to health threats in order to protect the health and security of the world. Data collection through disease monitoring and surveillance are important components of global health protection and security. Additionally, countries need to support each other and share resources during health emergencies. To be secure, countries must have the public health capacity to identify health threats, stop outbreaks from becoming epidemics, and save lives.

The Organization for Economic Co-operation and Development (OECD) defines life expectancy (LE) as the number of years, on the average, that an individual can expect to live assuming that the death rate at the time of the estimate remains constant. It is usually calculated at birth or a particular period and varies based on several factors including gender, socio economic status, country of birth, place of residence and death rate at the time of calculation. A decline in death rate results in a corresponding increase in actual life spans compared to the life expectancy calculated at the time of birth. However, an increase in death rate will result in decrease in actual life spans, compared to that calculated at birth. Life expectancy is a significant and frequently used health status indicator because it reflects the overall wellbeing and quality of life in a country or region. Increase in LE is a consequence of several factors, including higher standards of living, healthy lifestyle, better education and accessibility to health services. LE is also useful in understanding the demographics and needs of a population.

On the other hand, healthy life expectancy (HLE) is the number of years- on the average, that an individual is estimated and expected to live in good health at a specific age, after taking mortality and morbidity data into account, as well as the health status of the specified population. Unlike LE, HLE takes into consideration, factors such as quality of life and specific health status or conditions of the population. It can be used to determine and monitor the health status of populations. Using HLE estimates of countries, important needs such as future health services, health program evaluation and health trends analysis can be prepared for, and carried out effectively. In the United States, the Centre for Disease Control and Prevention (CDC) used data from the National Vital Statistics Systems (NVSS), U.S. Census Bureau and Behavioural Risk Factor Surveillance System (BRFSS) to estimate HLEs for persons aged 65 years, by sex and race. Findings from these calculations showed that from 2007 to 2009, women had a greater HLE than men at 65 years across the US while whites had a greater HLE than blacks, except in Nevada and New Mexico.

The difference between life expectancy (LE) and healthy life expectancy (HLE) is that the former describes the average number of years a person can expect to live based on current mortality rates for the population while the latter estimates the approimate healthy years that a person can expect to live on the basis of the current mortality rates plus the distribution of health status in the population. The difference between LE and HLE is a function of health status which represents the quality of the life. Consequently, LE is usually longer than HLE, however, the extra number of years expected to be lived may not necessarily be healthy and worthwhile. According to World Health Organization (WHO), in 2015, the global population had an average LE of 71.4 years at birth while the average HLE was 63.1 years. Considering the 2015 data presented by WHO, people remain very healthy and are able to work or contribute to the economy up to 63 years, however, at 71, chronic diseases become more prominent, significantly reducing the quality of life. It is important to know that these numbers are only averages and will differ from individual to individual based on more personalized and specific factors.

The Center for Disease Control and Prevention (CDC) describes smokeless tobacco and it’s products as nicotine-containing substances that can be consumed without burning. These products are consumed in various ways other than smoking, including chewing, sucking, dipping, sniffing, placing the product between the teeth and gum and application to the skin. There are numerous smokeless tobacco products around the world and they vary in composition, preparation and consumption methods and potential health risks. Smokeless tobacco is highly addictive since it still contains nicotine, and stopping it’s use can be as challenging as quitting smoking.

South and South-East Asia are locations with the highest prevalence of smokeless tobacco use. In these regions, smokeless tobacco is often served at social occasions and may contain slaked lime, areca nut, flavourings, and aromatic substances. Other areas where the consumption of smokeless tobacco is also evident include Nordic countries and North America, Venezuela, Uzbekistan, Kyrgyzstan, Sudan, Chad, Nigeria, Ghana and South Africa. In these parts of world, common products include Snus, Chimó, Nass, Tambook, Snuff and soluble tobacco such as tobacco lozenges, orbs, pellets, breath strips and toothpick-sized sticks. Some tobacco products are made like candy, containing contain sweeteners and flavors, however, they all have nicotine. Given the widespread international use and potential risks of smokeless tobacco, it is important to extensively assess its impact on health.

A 2010 study by Siddiqi et al. showed adult smokeless tobacco consumption data and estimated disease burden of over 100 countries. The estimates showed that the use of smokeless tobacco resulted in about 1.7 million DALYs lost and 62,283 deaths. The majority of the death were due to mouth, pharynx and oesophagus cancer. As expected, South-East, where the use of smokeless tobacco products is most prevalent, had the highest burden of death and disease. Furthermore, several studies have shown increased rates of leukoplakia in the areas of the mouth where tobacco is chewed or dipped. Leukoplakia is a cancerous painless grayish white patch, spot or sore in the mouth which usually clears when tobacco use is terminated. The likelihood of having leukoplakia increases with increase in the length of time oral tobacco is used. Additionally, tobacco use may cause teeth stains or decays, cavities, receding gums, bad breath and gum tissue irritation and disease, bone loss around the teeth and tooth loss. Given the above facts, it is quite obvious that all tobacco products are harmful, irrespective of their form, composition and method of consumption. Therefore, “smokeless” doesn’t translate to harmless as misconceived by a lot of people.

The use of smokeless tobacco results in significant but preventable global morbidity and mortality, especially from cancer. Consequently, health regulatory organizations such as CDC and World Health Organization need to consider the establishment of  smokeless tobacco regulations as part of tobacco control initiatives. Currently, WHO recommends that consumers must be informed on probable negative health effects by ensuring that health warnings and labelling are shown on smokeless tobacco products. In addition, further research should be conducted to assess nicotine and risks to individuals, as well as to identify health effects of changing patterns of smokeless tobacco use in populations.