The human health toll caused by a decline in wild pollinators has been quantified in a study led by Harvard T.H. Chan School of Public Health.
- An estimated 427,000 deaths each year have been linked to a drop in wild pollinators, such as bees.
- The world produces 3-5% less fruit, vegetables and nuts than it could with robust wild pollinator populations as human activities harm biodiversity.
- We must step up efforts to help pollinators, as they play a fundamental role not only for ecosystems but for human health as well.
Quantifying the toll on human health
Based on crop yields in 2020, the world produces 3-5% less fruit, vegetables, and nuts than it could with robust wild pollinator populations. This translates into an estimated 427,000 deaths each year caused by insufficient healthy food consumption and associated diseases, including heart disease, stroke, diabetes, and certain cancers, according to research led by Harvard T.H. Chan School of Public Health.
The study, published in December 2022 in Environmental Health Perspectives, claims to be the first to quantify the toll of insufficient animal pollinators on human health. The researchers found that lost food production was concentrated in lower-income countries but that the health burden was greater in middle- and higher-income countries, where rates of non-communicable diseases are higher.
The geographic distribution was somewhat unusual in that generally the health effects from global environmental change are centred among the poorest populations, in regions such as South Asia and Sub-Saharan Africa. Here, middle-income countries with large populations, such as China, India, Indonesia, and Russia, suffered the greatest burden. Lower-income countries lost significant agricultural income due to insufficient pollination and lower yields, potentially 10-30% of total agricultural value.
“The results might seem surprising, but they reflect the complex dynamics of factors behind food systems and human populations around the world. Only with this type of interdisciplinary modeling can we get a better fix on the magnitude and impact of the problem,” said co-author Timothy Sulser, senior scientist at the International Food Policy Research Institute.
The researchers used a model framework that included empirical evidence from hundreds of experimental farms across Asia, Africa, Europe, and Latin America examining ‘pollinator yield gaps’ for the most important pollinator-dependent crops, to show how much had been lost due to insufficient pollination. They then used a global risk-disease model to estimate the health impacts the changes could have on dietary risks and mortality by country, and calculated the loss of economic value from lost pollination in three case study countries.
Biodiversity loss threatens food production
Human activity is causing massive biodiversity losses, including 1-2% annual declines in insect populations, leading some to warn of an impending ‘insect apocalypse’ in the coming decades. According to a study published in Biological Conservation in February 2020, between 250,000 to 500,000 species of insects, or 5-10%, went extinct since the industrial era.
Changes in land use, harmful pesticides, and advancing climate change threaten wild pollinators, which are crucial insect species that pollinate 75% of the world’s crops. Between $235 billion and $577 billion in annual global crop output is at risk as a result of these losses, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services estimated.
Scientists are warning that we are pushing many ecosystems beyond recovery, resulting in insect extinctions and in turn the depletion of essential, irreplaceable services to humanity.
New data highlights need for immediate action
The study in Environmental Health Perspectives shows that protecting wild pollinators is important not only environmentally, but also economically and medically. It was released days before world leaders agreed on a Global Biodiversity Framework at COP15, which is intended to protect and restore nature.
“A critical missing piece in the biodiversity discussion has been a lack of direct linkages to human health,” said Samuel Myers, principal research scientist, planetary health, Department of Environmental Health and senior author of the study. “This research establishes that loss of pollinators is already impacting health on a scale with other global health risk factors, such as prostate cancer or substance use disorders.”
Lead author Matthew Smith, a research scientist in the Department of Environmental Health, concluded: “This study shows that doing too little to help pollinators does not just harm nature, but human health as well.”
