Environmental Change and Health: A summary

It is expected that climate change will cause approximately 250,000 additional deaths per year between 2030 and 2050. The potential health impacts of environmental change are not distributed equally across the globe or among social classes. Global warming may have some benefits in temperate regions, such as fewer winter deaths and an increase in crop yields. On the other hand, as we have seen throughout this blog series, diseases resulting from climate change, habitat destruction, and environmental contamination has, and will continue to have, a powerful effect on indigenous health.

What is health?

The World Health Organisation describes the concept of health as a 'state of complete physical, mental and social well-being and not merely the absence of disease or infirmity'. However, Green et al. acknowledge that in many ways, Indigenous views of health can be more complex, abstract, and multifaceted than the Western biomedical consensus. A sense of identity, ancestry, language and a connection to the land are also intrinsic to indigenous concepts of health. 

Aboriginal health care training

Pathogenic disease

Increasing global temperatures and extreme weather could create a more favourable environment for disease transmission. As I mentioned in previous blogs, persistent floods in Uganda have led to more outbreaks of waterborne diseases among the Batwa, and hot, dry conditions in Australia may cause a spike in bacterial diarrhoea and Dengue fever in the Aboriginal community. A similar situation is likely to be seen in Asia, where diarrhoea incidence is expected to increase as floods and droughts become more frequent and freshwater availability decreases. Droughts in particular can increase pathogen concentration, as the pathogens multiply at increased rates in less available water.

Lifestyle diseases

Diseases such as obesity, diabetes, and cancer are usually rare in populations surviving on a traditional diet. However, millions of Indigenous people now dwell in urban areas, and so their diets are often higher in calories, fat and salt than those a few generations before them.

In the U.S., the aforementioned illnesses are increasing among tribes as access to traditional food is restricted by pollution, urbanisation and policy changes. Pacific islanders also suffer from high levels of obesity due to an increased consumption of imported, processed food in place of traditional foods. Up to 80% of women in American Samoa are obese. Micronutrient deficiencies are also common, with anaemia being prevalent amongst pregnant women and children.

Environmental contamination

Whilst Arctic environments may appear pristine on the surface, indigenous peoples in the Arctic are some of the most chemically contaminated ethnic groups. Since the early 1970s, an accumulation of manmade chemicals in the Arctic raised concerns about toxic substances contaminating marine animals and humans. According to one paper published by Jens Hansen, Inuits are the highest exposed to heavy metals such as methyl mercury, as it accumulates in marine organisms, which the Inuits rely on for food. Another particularly dangerous group of chemical compounds is the Poly Chlorinated Biphenyls (PCBs). Using PCBs in products such as paints and fluorescent lighting is now banned, but those that have already been released into the environment will take a long time to break down. At high concentrations, PCBs can be lethal to humans, and at lower concentrations can disrupt hormones and damage reproductive and immune systems.

Since the publication of a study by Dewailly et al. in 1989, we have known that the breast milk of indigenous women in Quebec has a higher concentration of PCBs than anywhere else in the world. Diets in this region consist of large amounts of fish and meat, in which the chemical accumulates and enters the food chain. In the study, the average level of PCBs in non-indigenous populations in Quebec was around 0.77mg/kg, whilst levels in indigenous women averaged around 3.60mg/kg, and even reached 14.7mg/kg.

Aconitum heterophyllum

Traditional medicines

Biodiversity loss resulting from habitat degradation, invasive species, and climate change, reduces the availability of traditional remedies, such as medicinal plants. A ten-year study by Prakash Kala published in 2004 assessed the population status of medicinal plants in the Indian Himalayas. Of the 60 species studied, 22% where critically endangered, 16% were endangered and a further 27% were vulnerable.

According to the indigenous healers, approximately 45 different ailments can be treated with various parts of the plants included in the study. These medicinal plants face numerous threats, including habitat loss, introduction of alien species, over-grazing of livestock, climate change, unregulated tourism and commercial collection, and road construction. For example, the tubers Aconitum heterophyllum are traditionally used to treat diarrhoea and fever, but overexploitation and illegal collection has resulted in an Endangered classification by the IUCN.

Summary

Not only does environmental change increases the prevalence of diseases, through both the spread of pathogens and the loss of traditional diets, but also reduces the availability of traditional remedies that have been used for generations. The impacts of biodiversity loss most negatively affects marginalised groups, which often includes indigenous peoples, as health care is mostly unaffordable or inaccessible. Athough I haven't covered mental health in as much detail here, throughout the previous 'spotlight' posts I have explored how climate change and biodiversity loss also causes stress, depression, and grief, and that cultural identity and a connection to the natural environment is a key factor in Indigenous health.