This is the last of CHE’s public quarterly Top 10 lists. We have selected studies and issues that we feel are significant in the field of environmental health, either because of their impact, their implications or their insight. Topics are listed in no particular order. Comments are welcome, as is always true with our blog posts. Corrected in an update 1/6/2016.
- Climate change.
The Paris Agreement from the 21st Conference of Parties (COP21) in Paris is a potentially historic global agreement governing carbon dioxide reduction measures. The agreement still need to be joined by individual countries, and although the reduction targets are considered binding, there is no deadline for determining the targets or any mechanism of enforcement. Regardless, the agreement is considered “a turning point in the struggle to contain global warming” (New York Times).
Also on the issue of climate, the American Academy of Pediatrics released a statement, Global Climate Change and Children’s Health, stating that “failure to take prompt, substantive action would be an act of injustice to all children.”
- The role of extrinsic factors in the development of cancers.
Nature published an extensive analysis of the roles of intrinsic (genetic) and extrinsic (environmental) contributors to cancer and concluded “that cancer risk is heavily influenced by extrinsic factors.”
- Air pollution scope and effects.
The level of air pollution was recurring news, including Delhi’s levels that “would qualify as a public health emergency”, Beijing’s red alert, and European Environment Agency’s declaration that air pollution is the single biggest environmental health risk in Europe. Success stories could also be found, as in “The cities that are cleaning up their act.
Studies of impacts found a slight increase in violent crime in Chicago and more evidence that air pollution in Mexico City is associated with markers in children that are also linked to Alzheimer’s disease when measured later in life. Also, improvements under the Clean Air Act of 1970 have increased earning potentials: “A higher pollution level in the year of birth is associated with lower labor force participation and lower earnings at age 30.”
- Diabetes incidence.
The US Centers for Disease Control and Prevention (CDC) published data showing that at last the incidence of diabetes has stopped increasing and may be decreasing. However, diabetes is at least two distinct diseases with different etiologies, and so the picture is not as clear as the CDC report implies. CHE’s comments highlight that there is no evidence that type 1 diabetes incidence is declining, while some reports show increasing type 1 diabetes incidence in US children. Increasing evidence over the last several years shows environmental contributors to both types of diabetes.
- Hazards of fracking.
Concerned Health Professionals of New York and Physicians for Social Responsibility published Compendium of Scientific, Medical, and Media Findings Demonstrating Risks and Harms of Fracking (Unconventional Gas and Oil Extraction) highlighting “health risks ranging from air and water pollution to a newly emerging problem: leakage of methane and toxic gases from natural gas compressors, pipelines and other infrastructure.” The ongoing methane leak in California should draw attention to the warnings outlined in this report.
- Marine food chain collapse.
A study published in the Proceedings of the National Academy of Sciences of the United States of America found that the marine food chain is at risk of collapse due to ocean acidification and warming from anthropogenic carbon dioxide emissions. Fish and seafood provide a significant source of protein for much of the world’s human population, as this report highlights, making this an urgent environmental public health concern.
- Preventing type 1 diabetes.
A study published in JAMA Pediatrics found that early probiotic supplementation may reduce the risk of islet autoimmunity in children at the highest genetic risk of type 1 diabetes. This is the first demonstrated preventive intervention associated with decreased levels of antibodies linked to type 1 diabetes and is consistent with an important role of the intestinal microbiome in shaping the developing immune system. CHE has periodically explored the impact of various environmental factors on the microbiome and will continue to follow this rapidly developing field of interest inasmuch as there may be implications for other immune-related disorders as well.
- Antibiotic resistance.
The BBC published an article stating: “The world is on the cusp of a ‘post-antibiotic era’, scientists have warned after finding bacteria resistant to drugs used when all other treatments have failed.” dWarnings of antibiotic resistance date back more than 50 years, but this report is based on a new finding published in The Lancet describing the breach of the last group of antibiotics, polymyxins, by plasmid-mediated resistance and that the resistance can be transferred to neighboring bacteria. It is likely that resistance emerged after overuse of the antibiotic in farm animals. Antibiotic resistant infections in people are rapidly growing in countries around the world with few new pharmaceuticals in the research and development pipeline. Appropriate use and stewardship of antibiotics is not only the responsibility of healthcare providers but also of those using the largest amounts—farmers and ranchers in animal livestock production.
- Water fluoridation.
An extensive review by Cochrane, a highly regarded group recognized as representing an international gold standard for high quality, trusted information, concluded that “There is very little contemporary evidence, meeting the review’s inclusion criteria, that has evaluated the effectiveness of water fluoridation for the prevention of caries.” Most studies that met the criteria for review were conducted before 1975 when widespread use of fluoridated toothpaste was initiated. Many studies were at high risk of bias. The authors concluded that water fluoridation resulted in a 35% reduction in decayed, missing, or filled deciduous (baby) teeth and a statistically insignificant 26% reduction in decayed, missing, or filled permanent teeth. The risk of dental fluorosis resulting from fluoride exposure in drinking water at guideline levels varied from 12-40%. This review documents the limited evidence supporting the ongoing practice of fluoridating community drinking water supplies while concerns about safety of the practice continue to grow. An article from The Guardian provides additional commentary on the review.
- Lead poisoning.
We’ve known for millennia that lead is harmful, and yet children are still being exposed in large numbers around the world. Preventable exposures have been highlighted in recent news in Baltimore following Freddie Gray’s life and death and in Flint, Michigan,