Featured Research

from universities, journals, and other organizations

Low doses of arsenic cause cancer in male mice

Date:
July 8, 2014
Source:
National Institute of Environmental Health Sciences (NIEHS)
Summary:
Mice exposed to low doses of arsenic in drinking water, similar to what some people might consume, developed lung cancer, researchers have found. Arsenic levels in public drinking water cannot exceed 10 parts per billion (ppb), which is the standard set by the U.S. Environmental Protection Agency. However, there are no established standards for private wells, from which millions of people get their drinking water.

Lung tumors occur in adult male mice after being exposed to low levels of arsenic throughout their life. The 50 parts per billion (ppb) concentration is within the range to which humans are exposed.
Credit: NIEHS

Mice exposed to low doses of arsenic in drinking water, similar to what some people might consume, developed lung cancer, researchers at the National Institutes of Health have found.

Arsenic levels in public drinking water cannot exceed 10 parts per billion (ppb), which is the standard set by the U.S. Environmental Protection Agency. However, there are no established standards for private wells, from which millions of people get their drinking water.

In this study, the concentrations given to the mice in their drinking water were 50 parts per billion (ppb), 500 ppb, and 5,000 ppb. 50 ppb is the lowest concentration that has been tested in an animal study, and researchers say that because of differing rates of metabolism, mice need to be exposed to greater concentrations of arsenic in drinking water than humans to achieve the same biological dose and similar health effects.

The researchers used a model that duplicates how humans are exposed to arsenic throughout their entire lifetime. In the study, the mice were given arsenic three weeks before breeding and throughout pregnancy and lactation. Arsenic was then given to the offspring after weaning, and all through adulthood at concentrations relevant to human exposure. The researchers looked at the tumors in the adult offspring.

"This is the first study to show tumor development in animals exposed to very low levels of arsenic, levels similar to which humans might be exposed," said Michael Waalkes, Ph.D., lead author on the paper and director of the National Toxicology Program (NTP) Laboratory. "The results are unexpected and certainly give cause for concern."

Arsenic is present in the environment as a naturally occurring substance or due to contamination from human activity. Arsenic may be found in many foods, including grains, fruits, and vegetables, where it is present due to absorption from the soil and water. This study focused on inorganic arsenic, which often occurs in excess in the drinking water of millions of people worldwide, and has been previously shown to be a human carcinogen.

In the study, more than half of the male offspring mice developed significant increases in benign and malignant lung tumors at the two lower doses (50 ppb and 500 ppb). Female offspring also developed benign tumors at the lower concentrations. Interestingly, the researchers did not find significant increases in lung tumors in either sex at the highest dose (5,000 ppb).

"Although this is only one study, it adds to a growing body of evidence showing adverse health effects from very low exposures to arsenic, raising the possibility that no level of arsenic appears to be safe," said Linda Birnbaum, Ph.D, director of the National Institute of Environmental Health Sciences (NIEHS) and NTP.

The paper from the NTP Laboratory at NIEHS, part of NIH, appears in the Archives of Toxicology.


Story Source:

The above story is based on materials provided by National Institute of Environmental Health Sciences (NIEHS). Note: Materials may be edited for content and length.


Journal Reference:

  1. Michael P. Waalkes, Wei Qu, Erik J. Tokar, Grace E. Kissling, Darlene Dixon. Lung tumors in mice induced by “whole-life” inorganic arsenic exposure at human-relevant doses. Archives of Toxicology, 2014; DOI: 10.1007/s00204-014-1305-8

Cite This Page:

National Institute of Environmental Health Sciences (NIEHS). "Low doses of arsenic cause cancer in male mice." ScienceDaily. ScienceDaily, 8 July 2014. <www.sciencedaily.com/releases/2014/07/140708101548.htm>.
National Institute of Environmental Health Sciences (NIEHS). (2014, July 8). Low doses of arsenic cause cancer in male mice. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2014/07/140708101548.htm
National Institute of Environmental Health Sciences (NIEHS). "Low doses of arsenic cause cancer in male mice." ScienceDaily. www.sciencedaily.com/releases/2014/07/140708101548.htm (accessed October 1, 2014).

Share This



More Plants & Animals News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Dolphins Might Use Earth's Magnetic Field As A GPS

Dolphins Might Use Earth's Magnetic Field As A GPS

Newsy (Sep. 30, 2014) A study released Monday suggests dolphins might be able to sense the Earth's magnetic field and possibly use it as a means of navigation. Video provided by Newsy
Powered by NewsLook.com
How To Battle Stink Bug Season

How To Battle Stink Bug Season

Newsy (Sep. 30, 2014) Homeowners in 33 states grapple with stink bugs moving indoors at this time of year. Here are a few tips to avoid stink bug infestations. Video provided by Newsy
Powered by NewsLook.com
California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins