The environment can be a powerful modifier of the normal development and behavior of humans. Environmental effects on development include reduction in IQ from exposure to heavy metals such as lead, changes in puberty from exposure to endocrine disrupting chemicals, birth defects, and fetal loss. Birth defects are the leading cause of death in children, and those born with birth defects have a greater risk of illness and long-term disability than those born without birth defects. Environmental exposure during the most critical developmental times, such as preconception, pre-implantation, the fetal period, and early childhood, can lead to functional loss and developmental changes through genetic mutations and epigenetic change, among other mechanisms. Consequences of developmental changes include a lifetime of suffering and significant society costs in terms of resources, medical care, and lost productivity.
- Foodborne illness and food insecurity leads to malnutrition. Nutritional reductions to a developing fetus have lasting effects throughout life. Malnutrition and under-nutrition during pregnancy are a global cause of low birth weight and later developmental deficits
- Changes in the patterns and concentration of contaminants, such as mercury and lead, entering the marine environment can increase contaminations in seafood, which can lead to developmental effects including a reduction in IQ of the developing fetus
- Increase in weeds and pests leads to an increase in the use of herbicides and pesticides, resulting in increased exposure and increasing the risk of developmental changes
- Increase in prevalence of certain toxins, including certain metals, inorganic arsenic, PCBs, persistent organic compounds, in human environments as released by extreme weather events. These toxins have been known to be human carcinogens and can alter the immune system.
- Increases in the frequency and location of harmful algal blooms, increasing the amount of biotoxins in fish and seafood, leading to developmental effects if eaten by a pregnant woman
Mitigation and Adaptation
- Access to prenatal care and to early intervention services will be critical in preventing and treating birth defects.
- In areas where the availability of water is a concern, alternative water sources or reusing water can result in water of a lower quality, which can result in the additional use of toxic chemicals.
- Changes in energy source policies to reduce increase exposures to airborne metal particulates
- Understanding the impacts of changes in weather patterns and ecosystems on the incidence, exposure, and distribution of chemical contaminants and biotoxins known to cause developmental disorders
- Expanding the use of marine species as biomedical models and sentinels for understanding effects of contaminants and biotoxins on human reproduction and development
- Understanding the implications of mitigation strategies, including changes in energy policies and new technologies, on the production, use, and storage of heavy metals and chemicals that are known to cause developmental disorders
For more information, please visit the chapter on Human Developmental Effects in A Human Health Perspective on Climate Change (Full Report)(4MB) .