Featured Research

from universities, journals, and other organizations

Dartmouth Medical School Researchers Discover Heavy Metal Contamination In Northern Mexico

Date:
March 12, 1999
Source:
Dartmouth Medical School
Summary:
Dartmouth Medical School (DMS) researchers have discovered industrial pollution sites in northern Mexico that have higher than ever before reported levels of heavy metal contamination. Smelters in Torreón and Chihuahua constitute a serious environmental threat to people living near these industries, according to a report in the April issue of Environmental Health Perspectives, the monthly journal of the National Institute of Environmental Health Sciences.

LEBANON, N.H. -- Dartmouth Medical School (DMS) researchers have discovered industrial pollution sites in northern Mexico that have higher than ever before reported levels of heavy metal contamination. Smelters in Torreón and Chihuahua constitute a serious environmental threat to people living near these industries, according to a report in the April issue of Environmental Health Perspectives, the monthly journal of the National Institute of Environmental Health Sciences.

"This is one of the most heavily contaminated residential areas in the Western Hemisphere and it has never been studied," says James Sargent, MD, a principal author of the study, and a pediatrician at Children's Hospital at Dartmouth at Dartmouth-Hitchcock Medical Center and Dartmouth Medical School.

In July 1995, roadside dust samples were collected from residential areas within 2,500 meters of smelters and refineries located in the cities of Torreón, Monterrey, and Chihuahua. Smelters and refineries are known to be potential sources of heavy metal contamination such as arsenic, cadmium, and lead. These cities have dry, dusty climates with residential areas lacking any substantial ground cover such as grass or bushes. Without adequate ground cover, heavy metal pollutant-laden dust is more ubiquitous and airborne, increasing the likelihood that it will be ingested or inhaled.

In all three cities, heavy metal concentrations exceeded maximum acceptable levels established by the EPA for cleanup at U.S. Superfund sites. "Previous studies of heavy metal exposure in Mexico have focused primarily on lead in gasoline and household ceramics," said Sargent. "Other environmental contaminants such as cadmium and arsenic have largely been ignored."

Based on data from previous studies, Sargent estimates the average blood lead levels in children living within 1 mile of the Torreón smelter would be approximately 40 mcg/dL. "Anything over 20 mcg/dL is harmful to children," he said. For infants and young children, lead exposure has been shown to decrease intelligence (IQ) scores, slow their growth, and cause hearing problems. Exposure to high lead levels can badly damage the brain and kidneys of adults and children.

Sargent also fears that the levels of cadmium and arsenic exposure are higher than what's safe. "The cadmium levels in Torreón are higher than have ever been reported at industrial sites," he says. "Cadmium causes permanent damage to your kidneys and it is not easily excreted from the body." Cadmium also causes lung damage such as emphysema, as well as hypertension and osteoporosis. A suspected carcinogen, Cadmium increases the risk of lung cancer and prostate cancer.

Arsenic causes neurological and liver damage and has been shown to cause skin cancer. Inhaled arsenic can increase the risk of lung cancer -- this has been observed in humans exposed to high levels of airborne arsenic in or around smelters.

"We are very concerned by the levels of contamination in these areas, especially because the smelters are surrounded by residential neighborhoods," said Madeline Dalton, PhD, another DMS researcher on the study. "It suggests that these industries have not been adequately monitored for environmental safety. Clearly, further investigation is warranted."

The smelter in Torreón, a manufacturing and mining center with a population of about 500,000 people, is the largest nonferrous metallurgical complex in Latin America and the fourth largest in the world. The smelter in Chihauhua, historically a prosperous mining center, has been inactive since 1990. Samples from Monterrey were collected near an active lead crystal factory and an inactive lead refinery. Monterrey, a city of 3 million people, is a commercial capital in northern Mexico.

Other study authors include DMS researcher and pediatrician, Andrea Benin, MD, and Sandy Roda, MS, Kettering Laboratory, Department of Environmental Health, University of Cincinnati. The study was supported by an American Academy of Pediatrics resident research grant and a Helen's Fund grant from the Department of Pediatrics, Dartmouth-Hitchcock Medical Center.


Story Source:

The above story is based on materials provided by Dartmouth Medical School. Note: Materials may be edited for content and length.


Cite This Page:

Dartmouth Medical School. "Dartmouth Medical School Researchers Discover Heavy Metal Contamination In Northern Mexico." ScienceDaily. ScienceDaily, 12 March 1999. <www.sciencedaily.com/releases/1999/03/990312061036.htm>.
Dartmouth Medical School. (1999, March 12). Dartmouth Medical School Researchers Discover Heavy Metal Contamination In Northern Mexico. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/1999/03/990312061036.htm
Dartmouth Medical School. "Dartmouth Medical School Researchers Discover Heavy Metal Contamination In Northern Mexico." ScienceDaily. www.sciencedaily.com/releases/1999/03/990312061036.htm (accessed August 29, 2014).

Share This




More Earth & Climate News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Volcano Erupts on Papua New Guinea

Raw: Volcano Erupts on Papua New Guinea

AP (Aug. 29, 2014) — Several communities were evacuated and some international flights were diverted on Friday after one of the most active volcanos in the region erupts. (Aug. 29) Video provided by AP
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) — State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Scientists Have Figured Out Why Rocks Move In Death Valley

Scientists Have Figured Out Why Rocks Move In Death Valley

Newsy (Aug. 28, 2014) — The mystery of the moving rocks in Death Valley, California, has finally been solved. Scientists are pointing to a combo of water, ice and wind. Video provided by Newsy
Powered by NewsLook.com
Big Waves, Minor Flooding from Hurricane

Big Waves, Minor Flooding from Hurricane

AP (Aug. 27, 2014) — Thundering surf spawned by Hurricane Marie pounded the Southern California coast Wednesday, causing minor flooding in a low-lying beach town. High surf warnings were posted for Los Angeles County south through Orange County. (Aug. 27) Video provided by AP
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:
from the past week

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