Increasing concentrations of atmospheric carbon dioxide (CO2) lower the content of zinc and other nutrients in important food crops. Zinc defi ciency is currently responsible for large burdens of disease globally, and the populations who are at highest risk of zinc defi ciency also receive most of their dietary zinc from crops. By modelling dietary intake of bioavailable zinc for the populations of 188 countries under both an ambient CO2 and elevated CO2 scenario, we sought to estimate the eff ect of anthropogenic CO2 emissions on the global risk of zinc defi ciency.

Both short- and long-term exposures to fine particulate matter (PM2.5) are associated with mortality. However, whether the associations exist below the new EPA standards (12 μg/m3 of annual average PM2.5, 35 μg/m3 daily) is unclear. In addition, it is not clear whether results of previous time series studies (fit in larger cities) and cohort studies (fit in convenience samples) are generalizable to the general population. The objective of the study was to estimate the effects of low-concentration PM2.5 on mortality.

The largest assemblage so far of published data shows that C3 crops have decreased zinc and iron levels under CO2 conditions predicted for the middle of this century, with worldwide nutritional implications.