Arsenic linked to cardiovascular disease at EPA-regulated drinking water standards

November 13, 2008

When mice are exposed to arsenic at federally-approved levels for drinking water, pores in liver blood vessels close, potentially leading to cardiovascular disease, say University of Pittsburgh researchers in the Dec. 1 issue of the Journal of Clinical Investigation, available online Nov. 13. The study, while preliminary, also reveals how an enzyme linked to hypertension and atherosclerosis alters cells, and may call into question current Environmental Protection Agency standards that are based solely on risks for cancer.

In the study, Aaron Barchowsky, Ph.D., associate professor of environmental and occupational health at the University of Pittsburgh Graduate School of Public Health, and his research team looked at specialized cells in the liver called sinusoidal endothelial cells, which are tasked with removing wastes from blood and enabling nutrients to regulate metabolism. After exposing mice to 10 to 100 parts per billion (ppb) of arsenic over a two-week period, the cells were less able to remove damaged proteins from the blood and lost their characteristic pores or "windows," severely compromising the cells' ability to effectively exchange nutrients and waste. Dr. Barchowsky notes that despite their small size, mice are usually less sensitive to the effects of arsenic than people

The current EPA standard for arsenic in public water systems is 10 ppb, reduced from 50 ppb in 2006. The standard applies only to drinking water sources that serve more than 20 people.

"These results are important since this type of cellular dysfunction, over time, can impair the body's ability to clear fats and waste proteins that build up in blood vessels and can lead to cardiovascular diseases such as hypertension and atherosclerosis," said Dr. Barchowsky

According to Dr. Barchowsky, arsenic increased the activity of an enzyme called NADPH oxidase and the levels of oxidants it produces, compromising sinusoidal cell functions. Mice that lacked the enzyme did not have changes in liver blood vessels when exposed to arsenic and their cells were able to continue to function effectively.

"Our findings raise some concerns about whether current EPA-developed standards can effectively protect against cardiovascular risks posed by arsenic in drinking water," said Dr. Barchowsky. "We are especially concerned about water from individual wells in small, rural and semi-rural communities that are exempt from the EPA requirement and often contain levels of arsenic that exceed the EPA limit.

Next phases of the research will focus on further understanding how arsenic increases the production of oxidants by NADPH oxidase and determining effective preventative measures to lessen the impact of arsenic and other environmental exposures on the function of the endothelial cells. Additional studies will investigate the relationship between arsenic's effects on liver blood vessels and metabolism and disease-related changes in other blood vessels in the body.

Arsenic is a naturally occurring mineral primarily found in groundwater. Drinking high levels of arsenic over many years has been linked to increased risks for lung, bladder and skin cancers, as well as heart disease, diabetes and neurological damage.

Source: University of Pittsburgh

Explore further: Nutty stimulant revealed as anticancer tool

Related Stories

Entangled in the endothelium

October 7, 2016

LMU researchers have uncovered the underlying cause of a rare type of immunodeficiency syndrome, which severely impairs their ability to fight infections.

Cell's recycling team helps sound alarm on pathogens

January 22, 2015

Just as households have garbage disposals and recycling bins for getting rid of everyday waste, the cell has its own system for cleaning up unnecessary or defunct components. This process, known as autophagy, is also an efficient ...

Battling 'the largest mass poisoning in history'

July 14, 2015

International health experts have called it the largest mass poisoning in history, and it is still underway. Some 100 million people in southeast Asia have been drinking from shallow wells originally drilled to provide germ-free ...

Recommended for you

Baby teethers soothe, but many contain low levels of BPA

December 7, 2016

Bisphenol-A (BPA), parabens and antimicrobials are widely used in personal care products and plastics. The U.S. and other governments have banned or restricted some of these compounds' use in certain products for babies and ...

0 comments

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.