New research from the University of York to assess the pollution of freshwater across the globe has shown that a surprisingly high proportion of the world’s rivers are threatened by pharmaceutical pollution.
The study found that 43% of the world’s rivers have levels of pharmaceutical pollution that are of concern. Of the 61 active pharmaceutical ingredients about which there is global data available, the study found that there were five active pharmaceutical ingredients (API’s) that exceeded critical environmental concentrations while ten API’s exceeded the level at which no environmental effects could be expected.
In particular, the drugs loratadine (an anti-allergen), desvenlafaxine (an antidepressant), clotrimazole (used in antifungal creams), ketotifen (an anti-allergen), and fluoxetine (an antidepressant) were found to have concentrations above the critical limit. In particular, desvenlafaxine and loratadine were relatively regularly found to exceed critical limits.
The pollution of freshwater by pharmaceutical ingredients was found to differ per continent: generally, pharmaceutical concentrations were found to be most frequently above safe limits in Africa and Latin America, in particular for sulfamethoxazole (an antibiotic). In Asia, nicotine was the active ingredient most frequently found to be above safe levels, while in Europe, propranolol (a beta blocker used to treat cardiovascular and neurological conditions) was the most frequently cited active ingredient. For North America, sulfamethoxazole and nicotine were most common.
The study draws its conclusions from the data contained in an earlier, comprehensive assessment of the global occurrence of pharmaceuticals in rivers. This earlier study, by Wilkinson et al, monitored 1,052 sampling sites along 258 of the word’s rivers in 104 countries across all continents. The latter study helped to correct limitations in the availability of data on pharmaceutical pollution of freshwater beyond North America and Europe, where most of the research into this issue is conducted.