Bush Administration Stumbles on Arsenic Pollution — Again

[baby_bear]

I posted this on LBN this morning, but should have posted it here instead.

http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=102&topic_id=221450

s_m

[treepig]

1. the article you posted focuses on CCA-treated deck-wood

and is rather long on opinion and short on actual science.

in any event, a quick survey of the scientific literature by doing a PUBMED search ( http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed ) on "arsenic treated wood" seems to suggest that this aspect of environmental exposure to arsenic is rather benign in comparison with overall arsenic exposure (unless you're sawing or sanding the arsenic-treated wood), which could be a major emerging health problem.

here's a representative study -

Int J Hyg Environ Health. 2003 Aug;206(4-5):381-6.

Case studies--arsenic.

Chou CH, De Rosa CT.

Agency for Toxic Substances and Disease Registry, Division of Toxicology, Department of Health and Human Services, Atlanta, Georgia 30333, USA. [e-mail]

Arsenic is found naturally in the environment. People may be exposed to arsenic by eating food, drinking water, breathing air, or by skin contact with soil or water that contains arsenic. In the U.S., the diet is a predominant source of exposure for the general population with smaller amounts coming from drinking water and air. Children may also be exposed to arsenic because of hand to mouth contact or eating dirt. In addition to the normal levels of arsenic in air, water, soil, and food, people could by exposed to higher levels in several ways such as in areas containing unusually high natural levels of arsenic in rocks which can lead to unusually high levels of arsenic in soil or water. People living in an area like this could take in elevated amounts of arsenic in drinking water. Workers in an occupation that involves arsenic production or use (for example, copper or lead smelting, wood treatment, pesticide application) could be exposed to elevated levels of arsenic at work. People who saw or sand arsenic-treated wood could inhale/ingest some of the sawdust which contains high levels of arsenic. Similarly, when pressure-treated wood is burned, high levels of arsenic could be released in the smoke. In agricultural areas where arsenic pesticides were used on crops the soil could contain high levels of arsenic. Some hazardous waste sites contain large quantities of arsenic. Arsenic ranks #1 on the ATSDR/EPA priority list of hazardous substances. Arsenic has been found in at least 1,014 current or former NPL sites. At the hazardous waster sites evaluated by ATSDR, exposure to arsenic in soil predominated over exposure to water, and no exposure to air had been recorded. However, there is no information on morbidity or mortality from exposure to arsenic in soil at hazardous waste sites. Exposure assessment, community and tribal involvement, and evaluation and surveillance of health effects are among the ATSDR future Superfund research program priority focus areas. Examples of exposures to arsenic in drinking water, diet and pesticide are given.

for most people, the soil in their backyards is probably the largest factor contributing to arsenic exposure:

Int J Toxicol. 2003 Mar-Apr;22(2):109-28.

Widespread arsenic contamination of soils in residential areas and public spaces: an emerging regulatory or medical crisis?

Belluck DA, Benjamin SL, Baveye P, Sampson J, Johnson B.

Riskwriters, Ltd, Minneapolis, Minnesota 55406, USA.

A critical review finds government agencies allow, permit, license, or ignore arsenic releases to surface soils. Release rates are controlled or evaluated using risk-based soil contaminant numerical limits employing standardized risk algorithms, chemical-specific and default input values. United States arsenic residential soil limits, approximately 0.4- approximately 40 ppm, generally correspond to a one-in-one-million to a one-in-ten-thousand incremental cancer risk range via ingestion of or direct contact with contaminated residential soils. Background arsenic surface soil levels often exceed applicable limits.

. . . and, to re-iterate, it's probably not a good idea to build your own deck . . .

AIHA J (Fairfax, Va). 2002 Mar-Apr;63(2):166-71.

Exposure to wood dust and heavy metals in workers using CCA pressure-treated wood.

Decker P, Cohen B, Butala JH, Gordon T.

Novartis Pharmaceutical Corporation, Suffern, NY, USA.

Chemical pesticide treatment enables relatively nonresistant woods to be used in outdoor construction projects. The most prevalent procedure used to protect these woods is pressure treatment with chromium, copper, and arsenic (CCA). This pilot study examined the airborne concentration and particle size distribution of wood particles, chromium, copper, and arsenic at both outdoor (measured over the whole work day) and indoor (measured during the performance of specific tasks) work sites. At the outdoor residential deck construction sites, the arithmetic mean total dust concentration, measured using personal filter cassette samplers, was 0.57 mg/m3. The mass median aerodynamic diameter (da) of the outdoor wood dust was greater than 20 microm. Indoor wood dust concentrations were significantly greater than those measured outdoor and were job category-dependent. The highest mean breathing zone dust concentration, 49.0 mg/m3, was measured at the indoor sanding operation. Personal impactor sampling demonstrated that the mean total airborne concentration of arsenic, but not chromium or copper, was consistently above recommended occupational exposure levels at the indoor work site, and occasionally at the outdoor work sites. At the indoor sanding operation, the mean total chromium, copper, and arsenic concentrations were 345, 170, and 342 microg/m3, respectively. Thus, significant exposure to airborne heavy metals can occur as a result of indoor and outdoor exposure to CCA pressure-treated wood dust. Therefore, current standards for wood dust may not adequately protect workers from the heavy metals commonly used in CCA pressure-treated wood.

[baby_bear]

2. Sorry, but the articles you posted/linked to substantiate the risk

Although they don't go into the early-life exposures being more indicative of later-life cancers...

Thanks for the links to the articles. Arsenic is much worse than most of us thought, and there are much wose effects than skin lesions.

s_m

[treepig]

3. the point i was trying to make was

that your article almost largely focused on the threat of aresenic-treated wood (mostly used to make decks, patio furniture, etc) to children.

i stand by my assessment that this aspect of arsenic exposure is relatively minor in comparison with other sources of exposure (and by focusing on one of the minor hazards, doesn't that make it easier for the whole threat posed by arsenic exposure to be dismissed . . . because quite frankly, I don't think the epidemiology holds up to scrutiny - anything that is proposed to increase the incidence of cancer by one in a million is basically just conjecture)