Our body does not only suffer chronic stress due to pollutants. Psychosocial factors also play a part in our long-term health. The psychosocial relationship to health is a widely investigated field. We refer to two areas of investigation relevant to our work.

Thermal pollution is going to be a factor of increased importance due to climate change as it encompasses everything from region down to the density of buildings and even further to the materiality of the environment.

Light disrupts the circadian rhythms of humans and wildlife alike as well as lowering melatonin production, which results in sleep deprivation, fatigue, headaches, stress, anxiety, and other health problems.

Noise pollution is a pollutant that is manageable in moderation. People specifically experience the negative health outcomes of noise when it disrupts their sleep and ability to recover or focus.

Air pollution presents a particularly insidious hazard given that the disease affects respiratory and cardio-vascular systems. These two systems are sensitive to air pollution as air pollution directly damages the mechanics and as a consequence the function of lungs, heart, and the circulatory system.

Climate change is the greatest challenge facing society today. The trends of pollution, in particular air pollution, have been steadily growing in the last few decades and have reached record highs.

The recent COVID-19 pandemic has sent a reminder of the imminent effects of climate change in our society. It has further highlighted the fragility of the balance between humans and environment, and has clearly exposed biological inequity in our society.

There is a large consensus in the literature that meeting a threshold for air pollution levels is sufficient to guarantee health. Indeed, the World Health Organization (WHO) has set out specific thresholds for acceptable levels of pollution, which are used by governments across the world as golden standards. However, the human body is not naturally designed to live in continuously polluted environments.

Given that climate change and pandemics are posing an immediate threat to health and are disproportionately affecting deprived communities, healthcare costs are projected to increase significantly. Thus now, more than ever, it is necessary to review our definition of health and how we apply it.

A stressor is defined as a novel threatening environmental agent that alters the baseline human biological system in either of two ways: bringing the system to an unstable biological state, or slowing down the system’s internal response so that it cannot reach equilibrium.

Homeostasis is a long-debated concept in the field of neuroscience and immunology. The term was originally coined by Cannon, who defined it as “a condition - a condition which may vary, but which is relatively constant”. Recently, McEwen has provided a more comprehensive definition of HM, explaining it as the return to a predetermined set of physiological conditions of equilibrium of the body, following stress.

Allostasis and Allostatic Overload are states in which the system enters a dysregulated stress response. Non-communicable diseases have been shown to be associated with Allostasis.

In order to better understand why certain communities are being disproportionately affected by the incidence of non-communicable diseases, it is important to consider the environmental and psychosocial stressors that the community experiences daily. It is from these considerations that we propose a new term to describe the unequal distribution of stressors and their effects on health in our society: biological inequity.