The other day I learned that wordpress.com now supports embeds of CartoDB maps. This is pretty cool, and it inspired me to finish up a little project that I’ve been tinkering with for a while, in order to try out the new feature.

By the way, CartoDB is a web mapping tool that I think is one of the best interfaces available for creating interactive maps. You can make great looking maps quickly and easily, but there is also enough functionality to do more advanced stuff, like mess around with the CSS code.

This map shows estimates of how much mercury is on site at chlor-alkali plants per country. It distinguishes between countries that ban the export of mercury and those that don’t. This is important because chlor-alkali plants often contain hundreds of tons of mercury. When the facilities close the mercury can enter the commodity market where it can be used in artisanal gold mining.

The size of the bubbles reflects how many tons of mercury are estimated to be in chlor-alkali facilities in each country. Scroll, zoom, hover, or click for more details. The data are from the UNEP Global Mercury Partnership chlor-alkali inventory.

Technical CartoDB note: In order to distinguish (by bubble color) countries with and without export bans, I made two layers from the data table. However, because each set had a different range of values, the scale for the bubble size was different for each color. To fix this I manually changed the bubble size distribution cutoffs in the CSS tab. Is there an easier solution that I am missing?

Oh yeah, this is how you do the embed.