This was written by Mandy Warner, Climate and Air Policy Specialist for the Environmental Defense Fund:
Hundreds of thousands of babies are born in the U.S each year with enough mercury in their blood to impair healthy brain development. As they grow, these children’s capacity to see, hear, move, feel, learn and respond can be severely compromised. Given all of the risks of mercury it is not surprising that I felt nervous as I stood waiting, this past summer, for my hair test results at the booth run by the National Institute for Minamata Disease at the International Conference on Mercury as a Global Pollutant in Edinburgh, Scotland. I feared that my then-seven-month-old daughter had somehow been exposed to potentially unsafe levels of the toxin and was still being exposed through nursing.
Then the researchers in the booth handed me a paper with my results and I had one of the lowest levels measured at the conference, they cheerfully announced. After getting my results I was simultaneously relieved and frustrated. Frustrated because I remembered the many times when I was pregnant that I was standing at the fish counter or looking at a restaurant menu and having to research on my smartphone which fish was safest for me and my baby and most sustainable for the environment. The benefits of eating fish while pregnant for the mother and child are significant, and it is important that pregnant women have lots of safe fish food options and not be scared away from eating fish altogether. But we have a lot of work to do to make sure mothers (and all consumers) do not have to be full-time researchers in order to make healthy and safe food choices. We must continue and expand our work to reduce emissions of toxic mercury pollution from all sources.
The scope and complexity of that challenge could be seen at this international conference, where hundreds of science, industry, academic, and policy experts from around the globe gathered to discuss, among other things, implementing an international treaty on mercury pollution. The treaty is an important first step in reigning in global mercury pollution and will, for the first time, ensure countries that join take measures to reduce mercury air emissions from a variety of sources, like power plants. It will also reduce industrial and product use of mercury, address the supply and trade of mercury, and includes provisions regarding small scale mining. The treaty has been signed by about 140 nation-states. The U.S. signed the treaty in November.
At the conference I presented on the U.S. experience in regulating mercury from power plants and my colleague, Kritee, presented her research on how isotopic fingerprints can be used to find the influence of sunlight and microbes on the mercury content in water. At the conference, Kritee and I also learned more about the international scope of the mercury problem. There were presentations on the exposure of small-scale gold miners (including women and children, who are more vulnerable to impacts from mercury) to the toxin.
In the Arctic, mercury concentration in fish and wildlife are among the highest in the world even when there are no nearby major industrial sources due to mercury emissions that originate in distant places. Even consumption of rice grown in areas with high mercury content in soils and air is now understood to pose a significant threat as a pathway for mercury exposure.
Finally, climate change itself is exacerbating emissions of mercury, as Kritee explains. In the end, the conference was energizing and inspiring, though it’s clear that a tremendous amount of work remains if we are to tame the threat mercury poses. It’s also clear that the global nature of mercury emissions necessitates an international, cooperative solution to protect Americans and people around the world. 
I was fortunate enough to be able to spend some time after the conference touring Scotland with my daughter and husband. Maybe someday, when she’s older, I’ll be able to tell my daughter about her trip to Scotland and a big scientific conference. Perhaps by then I will be able to talk about the mercury problem as a success story in which the nations of the world joined to successfully overcome a global environmental and health challenge.