What is the environment? The most simple definition of environment is 'surroundings'. A person's environment can encompass their physical, social, and biological surroundings.

All organisms, including humans, need resources obtained from their environment. These can be physical resources, such as water, air, and shelter. Or they can be biological resources, such as food and mates. Unfortunately, not all interactions with the environment are positive. What is the environmental impact on human health and behaviour? We'll see the relation with our lyfestlye and some examples like radiation and disease. Keep reading to find out!

Environmental Impact on Human Health

Human health and wellbeing are linked to the natural environment. It's estimated that 12-18% of European deaths are related to environmental stressors.

Pollution

Pollution is a significant environmental problem that can impact human health. High levels of pollutants can lead to health issues such as heart disease, respiratory diseases, and some cancers.

People with lower incomes are more likely to live in polluted areas and have unsafe drinking water. Children and pregnant women experience a greater risk of pollution-related health issues.

Fig. 1 – Individuals living close to power stations are more likely to report respiratory complaints than the general population, unsplash.com.

Climate Change

Burning fossil fuels has led to greenhouse gas emissions, which not only cause pollution but also trap heat in the atmosphere and cause an increase in temperatures. Hotter weather has been associated with a range of health problems, such as:

• Heat stroke

• Chronic kidney problems

• Premature births

• Asthma

Environmental Impact on Human Behaviour

Our social environment can influence our behaviour. For example, you act differently during an exam than when you spend time with friends. The surrounding environment can also impact motivation. Sharing a communal space, such as a kitchen, with tidy people will encourage you to keep the area clean. However, if the other kitchen users are messy, you may find yourself less motivated to clean up after yourself.

Furthermore, light levels can impact a person's sleep and mood. Unnatural light exposure affects our circadian rhythms.

Insufficient levels of light during the daytime (either natural or artificial) can increase stress levels. On the other hand, too much light at night can negatively impact sleep and, thus, mood.

Behaviour and Mood in the Natural Environment

The natural environment is vital to human wellbeing. As a result, cities need to have access to green and blue spaces.

• Green spaces are areas of vegetated land, particularly within an urban area.

Access to green space has been associated with better cognitive functioning, improved impulse control, and decreased rates of mental health problems such as anxiety and depression.

• Blue spaces are areas of visible water, especially within urban areas.

Many people view blue space as restorative and peaceful; it has been linked to reduced stress levels. Furthermore, the nearby blue area encourages physical activity.

Fig. 2 – Urban blue space in Amsterdam, unsplash.com.

Environmental Impact on Humans: Lifestyle & Health

Interactions with the environment looks at the macro-effects and micro-effects of the interactions between organisms and their environment by introducing the effects of lifestyle on the delicate balance within the human body.

The relationship between health and disease has always gone hand in hand. However, with current knowledge, it is believed that health is more than just the absence of illness or a balance of both physical and mental wellbeing. Many factors and lifestyle choices can influence health.

Disease can be split into two main categories, communicable diseases are infectious, while non-communicable diseases are not.

Recognising how lifestyle choices can affect the risk of developing a non-communicable disease, with the main risk factors including:

• Smoking

• Excessive use of alcohol

• Lack of exercise

• Unhealthy diet

Cardiovascular disease is a significant non-communicable disease, responsible for one-third of deaths globally. Some of the symptoms of this broad disease include heart palpitations, fatigue, and chest pain. Understanding the signs and methods of treatment, such as medication, and lifestyle changes, including limiting the risk factors mentioned above, are necessary to know how to prevent and treat this condition.

Homeostasis is a process carried out by the human body. It is involved in the regulation of internal conditions in response to internal and external changes. Some lifestyle or genetic mutations can lead to diabetes, another non-communicable disease that affects insulin homeostasis. Diabetes has two types, which manifest in the body differently. Prevention and treatment of diabetes are about knowing when to use insulin injections or implementing lifestyle changes.

Looking at the female human reproductive hormones, such as progesterone, oestrogen, and LH (luteinising hormone), has helped scientists and healthcare professionals understand how to utilise these hormones in contraception or even treating infertility.

Environmental Impact on Humans: Radiation

Exposure to radiation from our surroundings, particularly ionising radiation, can damage living cells and eventually lead to the development of malignant tumours. Understanding this exposure risk (which can often be over or under-estimated) is one way humans can protect themselves.

The electromagnetic spectrum is the distribution of varying frequencies and wavelengths of electromagnetic radiation. The spectrum is organised in sections, from highest to lowest energy: gamma, X-rays, UV (ultraviolet), visible light, infrared and radio waves. When a photon of light hits an electron and absorbs enough energy, it can jump to the next energy state. If the electron becomes unstable, it can cause the atom's nucleus to become radioactive!

Radioactive decay is a process that takes place in unstable nuclei. There are four types of radioactive decay, each with different penetration properties. With gamma rays being the most penetrating! Understanding the various penetration properties can help protect against harmful ionising radiation.

The radioactive decay rate depends on an isotope's half-life.

Exposure to harmful X-rays and gamma rays can damage the body and lead to cancer. Reducing the risk of exposure to these ionising radiations can help to prevent its associated hazards and health risks.

Environmental Impact on Humans: Disease

Disease can manifest in the body in several ways. Still, the human body is actually quite smart and has many processes and defences that can help to protect it from pathogens. Diseases which are caused by pathogens are known as communicable diseases.

Learning about the causes and spread of infectious diseases, including sexually transmitted infections (STD) and HIV, is essential to minimise transmission. The human body has multiple methods of defending itself against pathogens, from limiting entry via physical barriers to specially adapted white blood cells in the immune system. Sometimes, however, our bodies need an extra boost as these defences can be breached. This is where the development of medications, such as antibiotics, comes in handy. Antibiotics are valuable drugs for the treatment of bacterial infections.

Vaccinations are crucial, too. They help to protect the population from many diseases such as influenza and even COVID! Vaccines work by triggering the immune response to recognise and fight disease-causing organisms.

^{1. British Heart Foundation, Global Heart & Circulatory Diseases Factsheet, 2022}

^{2. European Environment Agency, Environment and health, 2022}

^{3. Newport Institute, How Does Your Physical Environment Affect You and Your Mental Health?, Mental Health, 2021}

^{4. World Health Organization, Noncommunicable diseases, 2022}