Asbestos Abatement >> Chrysotile

Abstract This review provides a basis for substantiating both kinetically and pathologically the differences between chrysotile and amphibole asbestos. 
Chrysotile, which is rapidly attacked by the acid environment of the macrophage, falls apart in the lung into short fibers and particles, Chrysotile while the amphibole asbestos persist creating a response to the fibrous structure of this mineral. 

Inhalation toxicity studies of chrysotile at non-lung overload conditions demonstrate that the long (>20 µm) fibers are rapidly cleared from the lung, Chrysotile are not translocated to the pleural cavity and do not initiate fibrogenic response. 

In contrast, long amphibole asbestos fibers persist, Chrysotile are quickly (within 7 d) translocated to the pleural cavity and result in interstitial fibrosis and pleural inflammation. 

Quantitative reviews of epidemiological studies of mineral fibers have Chrysotile determined the potency of chrysotile and amphibole asbestos for causing lung cancer and mesothelioma in relation to fiber type and have also differentiated between these two minerals. These studies have been reviewed in light of the frequent use of amphibole asbestos. 

As with other respirable particulates, there is evidence that heavy and Chrysotile prolonged exposure to chrysotile can produce lung cancer. The importance of the present and other similar reviews is that the studies they report show that low exposures to chrysotile do not present a detectable risk to health. 

Since total dose over time decides the likelihood of disease occurrence and Chrysotile progression, they also suggest that the risk of an adverse outcome may be low with even high exposures experienced over a short duration. Numerous investigators have suggested that there is likely to be a cumulative chrysotile exposure below which there is negligible risk of asbestos-related diseases. 

However, to date, little research has been conducted to identify an actual "no-effect" exposure level for chrysotile-related lung cancer and Chrysotile mesothelioma. The purpose of this analysis is to summarize and present all of the cumulative exposure-response data reported for predominantly chrysotile-exposed cohorts in the published literature. 

Criteria for consideration in this analysis included stratification of relative risk or mortality ratio estimates by cumulative chrysotile exposure. Over 350 studies were initially evaluated and subsequently excluded from the analysis due primarily to lack of cumulative exposure information, Chrysotile lack of information on fiber type, and/or evidence of significant exposures to amphiboles. 

Fourteen studies meeting the inclusion criteria were found where lung cancer risk was stratified by cumulative chrysotile exposure; Chrysotile four such studies were found for mesothelioma. All of the studies involved cohorts exposed to high levels of chrysotile in mining or manufacturing settings. 

The preponderance of the cumulative "no-effects" exposure levels for lung cancer and mesothelioma fall in a range of approximately 25-1,000 fibers per cubic centimeter per year (f/cc-yr) and 15-500 f/cc-yr, respectively, and Chrysotile a majority of the studies did not report an increased risk at the highest estimated exposure. 

Sources of uncertainty in these values include errors in the cumulative exposure estimates, conversion of dust counts to fiber data, and Chrysotile use of national age-adjusted mortality rates. Numerous potential biases also exist. 

For example, smoking was rarely controlled for and amphibole exposure did in fact occur in a majority of the studies, Chrysotile which would bias many of the reported "no-effect" exposure levels towards lower values. 

However, many of the studies likely lack sufficient power (e.g., due to small cohort size) to assess whether there could have been a significant increase in risk at the reported no-observed-adverse-effects level (NOAEL); Chrysotile additional statistical analyses are required to address this source of bias and the attendant influence on these values. 

The chrysotile NOAELs appear to be consistent with exposure-response information for certain cohorts with well-established industrial hygiene and Chrysotile epidemiology data. 

Specifically, the range of chrysotile NOAELs were found to be consistently higher than upper-bound cumulative chrysotile exposure estimates that have been published for pre-1980s automobile mechanics (e.g., 95th percentile of 2.0 f/ cc-yr), Chrysotile an occupation that historically worked with chrysotile-containing friction products yet has been shown to have no increased risk of asbestos-related diseases. 

While the debate regarding chrysotile as a risk factor for mesothelioma will likely continue for some time, future research into nonlinear, Chrysotile vermiculite is mined at three U.S. facilities and in other countries which have lower levels of asbestos contamination in the finished material. threshold cancer risk models for chrysotile-related respiratory diseases appears to be warranted.

Basic Facts About Bats And Bat Exclusion

Little Brown Bat Did You Know? Bats are the only mammals that can fly. They are insect-eating machines, eating thousands of mosquitoes and other flying insects in a single night. Bats use echolocation (rapid pulses of sound that bounce off an object) to detect and Animal Damage Basic Facts About Bats And Bat Exclusion catch insects.   read more..

Tools For Restoring Flood Damaged Electronics

Other manufacturer-supplied test data shed light on the typical behavior of tantalum polymer capacitors after exposure to various environmental stresses. Sanyo provided data that describe the typical response of their capacitors to dry heat, moisture, solder reflow conditions, and Electronic Restoration Tools For Restoring Flood Damaged Electronics DC   read more..

Lead Testing In Soil

Is there lead in the soil outside your home? It may have gotten there from paint on the outside of the building or from industry. Or it may have come from car exhaust from the days when gasoline contained lead. Children can be poisoned if they play in soil that has lead in it or if someone trac  read more..

Removing Smoke Odors From Fire damaged Furniture

The nonprofit NFPA's (National Fire Protection Association) Fire Safety Educational Memorial Fund Committee last month named the Seattle Hazmat Response Team, Seattle, Fire Damage Removing Smoke Odors From Fire damaged Furniture Washington as the 2004 recipient of the Warren E. Isman Educational Grant.

The team will use the grant to atten  read more..

Water Damage From Leaking Water Heater

Water heater leaks are usually quite obvious and you will discover substantial amounts of water on the floor around your heater. Normally, the first sign of a heater problem is water dripping from the bottom of the jacket. This indicates that the tank has corroded through. The cure may be installati  read more..

Ice Storm Cleanup

Debris removal supervision strategy help cities prepare for natural disaster related Debris Removal Ice Storm Cleanup and finally enhance the recovery procedure. To be operative, however, these strategies need to recognize crucial elements of the debris removal procedure, including the prequalification of debris removal   read more..

Asbestos Abatement Services

The project dates must be consistent with the contract documents, but must also reflect the actual dates that the contractor anticipates being on site. For example, if the contract requires that the work be conducted in June but the work will require only one week for completion, the notification mu  read more..

Mold Remediation

A constant presence of humidity in no time will start to form mold, and because in most cases mold will reproduce by forming spores that are released into the air. As the mold spores land on a moist, damp surface they will begin to multiply. Mold will penetrate right through porous materials   read more..

Water Flooded Carpet After Hurricane

What type of disinfecting solutions or cleaners should I use? For cleaning surfaces such as wooden furniture, hard flooring, plastic items, etc., household cleaning products such as non-abrasive liquid or powdered kitchen cleaners or liquid dish soap mixed with water Water Extraction Water Flooded Carpet After Hurricane are fine.    read more..

How To Test For Lead Paint Poisoning

Appropriate follow-up medical examinations or consultations may also be provided for employees who have been temporarily removed from exposure under the medical removal protection provisions of the standard.(See Part IX, below.) The standard specifies the minimum content of pre-assignment and [  read more..