sweating

We are often advised to avoid eating green areas on potatoes. The green comes from chlorophyll that occurs naturally when potatoes are exposed to light. It is harmless but when it is there, it can be accompanied by a natural toxin – a substance called solanine, which is a steroidal glycoalkaloid or SGA. Sunlight can produce solanine as well as chlorophyll. Solanine is produced by plants to protect them from insects.

Solanine is bitter tasting so one is unlikely to consume much of it. But consuming enough of it can lead to gastrointestinal complications like diarrhea, abdominal pain, vomiting, and sweating.

Researchers at the University of California Riverside have discovered a way to eliminate toxic compounds from potatoes, making them safer to eat and easier to store. They have identified a key genetic mechanism in the production of SGAs. They found a specific protein that controls the production and believe it will be possible to control where and when SGAs are produced. Thus, it may be possible to have SGAs present in the leaves of potato plants, thereby protecting them from insects, while having none in the potatoes themselves. By limiting SGAs to non-edible parts of plants, they can be safer and more versatile plants. For example, modified potatoes could be stored in sunny places without worry and would always be safe to eat.

Plants have evolved ingenious ways to balance growth, reproduction, and defense. Our growing understanding of these mechanisms can allow people to redesign crops to meet modern needs, increase food safety, and reduce food waste.

**********

Web Links

Growing safer spuds: Removing toxins from potatoes

Photo, posted October 14, 2013, courtesy of Elton Morris via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

On hot, sticky summer days, one often hears the expression “it’s not the heat, it’s the humidity.” That isn’t just an old saw; it is a recognition of what might be the most underestimated direct, local danger of climate change. Extreme humid heat events represent a major health risk.

There is an index called “wet-bulb temperature” that is calculated from a combination of temperature and humidity data. The reading, which is taken from a thermometer covered in a wet cloth, is related to how muggy it feels and indicates how effectively a person sheds heat by sweating. When the wet-bulb temperature surpasses 95^o Fahrenheit, evaporation of sweat is no longer enough for our bodies to regulate their internal temperature. When people are exposed to these conditions for multiple hours, organ failure and death can result.

Climate models project that combinations of heat and humidity could reach deadly thresholds for anyone spending several hours outdoors by the end of this century.

Dangerous extremes only a few degrees below the human tolerance limits – including in parts of the southwestern and southeastern US – have more than doubled in frequency since 1979. Since then, there have been more than 7,000 occurrences of wet-bulb temperatures above 88^o, 250 above 91^o, and multiple reading above 95^o. Even at lower wet-bulb temperatures around 80^o, people with pre-existing health conditions, the elderly, as well as those performing strenuous outdoor labor and athletic activities, are at high risk.

More research is needed on the factors that generate extreme wet-bulb temperatures as well as the potential impacts on energy, food systems, and human security.

**********

Web Links

Dangerous Humid Heat Extremes Occurring Decades Before Expected

Photo, posted April 16, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Growing safer potatoes

Web Links

Extreme Heat And Humidity | Earth Wise

On hot, sticky summer days, one often hears the expression “it’s not the heat, it’s the humidity.” That isn’t just an old saw; it is a recognition of what might be the most underestimated direct, local danger of climate change. Extreme humid heat events represent a major health risk.

Web Links