Study shows climate change makes some chemicals more toxic to aquatic life

Jun 28, 2011

Some areas of the southern United States are suffering from the longest dry spell since 1887 and a new Baylor University study shows that could prove problematic for aquatic organisms.

The Baylor study found that drought conditions make some chemicals in the environment more toxic to fish and other aquatic life. Specifically, the study found that drought conditions exacerbate the magnitudes of the natural pH shifts in the water. This is important, the researchers said, because some contaminants in the water, such as ammonia, are more toxic to aquatic life depending on the . Also, more than 75 percent of the essential drugs described by the and approximately one-third of modern pesticides have ionizable groups of compounds. These "weak base" compounds when dispersed in the environment can become more toxic to fish when surface are high.

The findings appear on-line in the journal Integrated Environmental Assessment and Management.

"The importance of this work is it shows that we may be underestimating or overestimating the adverse effects of some chemicals on fish," said study co-author Dr. Bryan Brooks, associate professor of environmental science and biomedical studies and director of environmental health science at Baylor. "How , especially those influenced by climatic changes, impact fluctuations of the water's pH level is just now emerging as an area of concern in regards to making certain chemicals more toxic and more likely to accumulate in fish."

The Baylor researchers took samples at different times over the course of two years at 23 streams across the southern U.S. and measured how ecosystem production and respiration, dissolved , the amount of phosphorus and nitrogen, and pH level changed over the course of a day. The researchers found that in the year that was one of the driest on record, the fluctuations of the water's pH level was extreme and coincided with increased toxicity to .

"Future water scarcity associated with global climate change and altered precipitation patterns may profoundly impact in-stream flows in semiarid regions, which have direct implications for water resource management," said study co-author Dr. Ted Valenti, a former Baylor doctoral student. "Predicting the cumulative effects of climatic variability on the risk of contaminants may require a significant shift in the environmental assessment and management approaches for freshwater systems."

Explore further: Extreme weather in the Arctic problematic for people, wildlife

Provided by Baylor University

3.7 /5 (3 votes)
add to favorites email to friend print save as pdf

Related Stories

Study: Range of pharmaceuticals in fish across US

Mar 25, 2009

(AP) -- Fish caught near wastewater treatment plants serving five major U.S. cities had residues of pharmaceuticals in them, including medicines used to treat high cholesterol, allergies, high blood pressure, bipolar disorder ...

EPA: Decrease in toxic chemical releases

Apr 13, 2006

A U.S. Environmental Protection Agency report said Wednesday toxic chemicals released into the environment decreased 4 percent from 2003 to 2004.

Study finds common fire retardant harmful to aquatic life

May 24, 2011

A new study by Baylor University environmental health researchers found that zebra fish exposed to several different technical mixtures of polybrominated diphenyl ethers (PBDEs) – a common fire retardant – during ...

Recommended for you

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.