In this article, we explore why cumulative risk is such a key concern, how it affects human health and ecosystems, and how we can better manage it.
Cumulative risk refers to the total risk of exposure to more than one stressor or agent over a lifetime. Chemical, biological, physical, and even social stressors are all factors. Instead of looking at risks individually, cumulative risk assessment looks at how the stressors interact and affect an individual's or community's general health.
For example, a person might be exposed to low air pollution, contaminated water, inadequate housing, and too much stress brought on by poverty. Each might be tractable on its own, but together they can significantly increase the risk for illnesses such as asthma, heart disease, and mental illness.
Here is why cumulative risk is such a critical issue:
In the real world, people are exposed to more than one pollutant or stressor. For example, a single person living in an urban industrial area will be exposed simultaneously to air pollution, noise, water pollution, and socioeconomic stress. Traditional risk assessment does this to some extent. This makes cumulative risk assessment realistic and significant to understand the real burden imposed upon people and communities.
Cumulative dangers can compound each other. Exposures to air pollution and high degrees of stress may combine to produce more severe respiratory problems than either alone. Studies have discovered that simultaneous exposure to multiple chemicals can bring about synergistic effects — in which the combined result is greater than the addition of individual risks. This means that seemingly "safe" single levels for multiple exposures may, when added up, be dangerous.
Cumulative risk is a matter of social justice. Low-income communities, children, the old, and minority populations tend to be exposed in environments where a number of stressors overlap. These populations are likely to have higher levels of exposure and lower access to healthcare, therefore leading to health inequalities. It is critical to understand cumulative risk to guide the development of fair public health policies.
Most current environmental and public health regulations have single-substance reviews. For example, air and water quality regulations usually consider each pollutant in isolation. This leaves a gap in regulation where cumulative effects of multiple substances are not adequately considered. Ignoring cumulative risks underestimates the true health burden, as well as denies vulnerable populations protection.
Cumulative exposure to two or more stressors over long times will cause chronic diseases. These include respiratory diseases, cancer, and neurological diseases to cardiovascular disease, and mental illness. Because the latency of these diseases is long, tracing them back to their origins is out of the question, and therefore the relevance of researching cumulative risk towards preventive health and long-term public safety.
Here are some examples of cumulative risk in the real world:
The Flint, Michigan water crisis is a perfect case in point. Folks were already fighting poverty, malnourishment, and crime. When lead-contaminated water entered the picture, the combined burden was devastating. Children of Flint developed lead poisoning, delayed development, and long-term physical and mental damage.
Farm workers in both developed and developing countries share similar exposures to pesticides, low-quality housing, inadequate diets, and overlong workdays. Cumulative exposure in such cases is interpreted as a higher number of respiratory diseases, reproductive disorders, and cancers. In addition, such populations are usually deprived of health centers, elevating the cumulative impact further.
In the majority of urban settings, especially in low-income communities, individuals live near highways or industrial sites. Such locations may contain more PM2.5, lead, mold, noise, and crime that, as a combination, increase the cumulative risk of asthma, cardiovascular disease, and psychological stress. Children in such environments typically perform worse in school and experience developmental issues — an immediate effect of cumulative exposure.
Here is how you can overcome the challenges faced due to cumulative risk:
Researchers and policymakers need to re-evaluate traditional risk assessment models and include multiple stressors, both chemical and non-chemical. Some of the tools that will be used to overcome risk at the local level include Geographic Information Systems (GIS), as well as community health mapping.
Governments must recognize and respond to the inequities in cumulative risk exposure. This includes investing in infrastructure, improving access to healthcare, and regulation of industry around at-risk populations.
Public awareness about cumulative risk makes communities capable of pushing for cleaner and healthier environments. Community-led data collection and participatory research also guarantee local involvement in policy-making.
Health, housing, environmental, and education agencies must collaborate to address cumulative risk from all directions. Silo work will not suffice for an issue as complex and integrated as cumulative exposure.
Cumulative risk is not a conceptual notion — it is a real and growing problem affecting the lives of millions of people all over the world. Overlooking combined effects of several stressors leads to risk underestimation, policy breakdown, and continuous damage to those exposed.
Recognize cumulative risk by joining risk management training courses at London Crown Institute of Training and learn about the effective steps to protect people and the planet. Policymakers, scientists, and societies need to work together to identify, assess, and manage cumulative risk — before the cost becomes irreversible.
