Starving from Within

Stewing in our chemical effluent

Beriberi is a deficiency of vitamin B1, also known as thiamine. It used to be a big problem for many human populations, especially those on long sea journeys, but these days it is easily prevented with fortified foods such as cereals.

However, an alarming deficiency in B1 is occurring in fish and birds. This was first detected in the 1980s, in Baltic seabirds so deficient in thiamine that they could not fold their wings, sing, or stand on their own legs.

Thiamine deficiency has since been reported in multiple species and food webs, from giant moose to little minnows, in particular places and periods. In affected populations it can impair survival and reproduction, although the evidence does not support describing it as a universal, single-cause collapse of the entire food chain.

The causes remain uncertain. The deficiency’s spread across such different species may reflect several mechanisms: changes in how thiamine passes up the food web, less of it in the diet, pollutants, or some combination of these. Research continues, and the ecological consequences could be serious if widespread deficiencies persist without being understood.

One hypothesis worth investigating is a role for endocrine-disrupting chemicals. There are reported interactions between bis(2-ethylhexyl) phthalate (DEHP) and thiamine metabolism in the liver, but this does not establish DEHP as the cause of wildlife deficiency.

Another potential factor is pollution runoff, especially mercury. Thiamine contains sulfur, which mercury binds to readily, but the ecological link between mercury exposure and wildlife thiamine deficiency remains uncertain. Coal combustion remains an important anthropogenic source of mercury pollution, whose effects can persist long after a plant closes.

We should invest more in water treatment, using activated carbon for many organic pollutants and membrane filtration where carbon falls short. No single filter removes every endocrine disruptor and heavy metal, but cleaner waterways protect our species and others.