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Pleural mesothelioma and lung cancer risks in relation to occupational history and asbestos lung burden - cut to size polycarbonate

by:Cailong     2019-08-14
Pleural mesothelioma and lung cancer risks in relation to occupational history and asbestos lung burden  -  cut to size polycarbonate
We have a population-
A basic study of patients with a career history and measuring occupational exposure to workers and a common population with a burden on the lung of asbestos.
The relationship between lung burden and risk, especially at environmental exposure levels, will enable future mesothelioma rates for people born after 1965 who have never installed asbestos to be predicted from the asbestos lung burden
Methods after the individual interview, the lung samples of 133 patients with squamous cell carcinoma and 262 patients with lung cancer were counted with more than 5 µm of asbestos fibers using transmission electron microscopy.
The ORs of the Inter-mesothelioma were transformed into lifetime risks.
As a result, the risk of lifelong melanoma is about 0.
02% 1000 over 100 dry lung tissue per gram of tremolite
Folding ranges from 1 to 4 of the most exposed construction workers to less than 500 of the majority of the population.
The asbestos fiber counted is armite (75%), crocidolite (18%)
Other horned rocks (5%)
Asbestos (2%).
Conclusion The approximate linearity of dose response and lung load measurement in young people will provide a reasonable and reliable prediction for those born since 1965, and their risk is not yet seen nationwide.
The burden of recently born persons will indicate the continuing occupational and environmental hazards under the current asbestos control regulations.
Our results confirm the primary contribution of armite to the incidence of melanoma in the UK and the substantial contribution of non-melanoma
Professional contacts, especially women.
We conducted a population survey.
A basic study of patients with a career history and measuring occupational exposure to workers and a common population with a burden on the lung of asbestos.
The relationship between lung burden and risk, especially at environmental exposure levels, will enable future mesothelioma rates for people born after 1965 who have never installed asbestos to be predicted from the asbestos lung burden
Methods after the individual interview, the lung samples of 133 patients with squamous cell carcinoma and 262 patients with lung cancer were counted with more than 5 µm of asbestos fibers using transmission electron microscopy.
The ORs of the Inter-mesothelioma were transformed into lifetime risks.
As a result, the risk of lifelong melanoma is about 0.
02% 1000 over 100 dry lung tissue per gram of tremolite
Folding ranges from 1 to 4 of the most exposed construction workers to less than 500 of the majority of the population.
The asbestos fiber counted is armite (75%), crocidolite (18%)
Other horned rocks (5%)
Asbestos (2%).
Conclusion The approximate linearity of dose response and lung load measurement in young people will provide a reasonable and reliable prediction for those born since 1965, and their risk is not yet seen nationwide.
The burden of recently born persons will indicate the continuing occupational and environmental hazards under the current asbestos control regulations.
Our results confirm the primary contribution of armite to the incidence of melanoma in the UK and the substantial contribution of non-melanoma
Professional contacts, especially women.
Background and aimsA there is still a large amount of asbestos residue in many old buildings, and concerns continue to be raised about the environmental and occupational exposure of occupants during the maintenance, renovation and removal of homes, schools and workplaces
The resulting tumor risk cannot be calculated by extrapolation of historical occupational cohort studies, because even for the public or plumber, lifetime average air exposure levels in breathing areas cannot be estimated, electricians and other construction or demolition workers.
Asbestos lung burden is the only cumulative life exposure indicator that can be reliably measured in the populationbased study.
So we developed a dose response model in the population
A series of patients with occupational history of intertumor and resection of lung cancer obtained through personal interviews and measurement of lung burden.
This will enable the lung burden of occupational groups and general populations to predict the future incidence of skin disease, which was born after 1965 and started working after 1980, when the UK almost stopped using asbestos (figure 1).
Download the new tabDownload powerpointFigure1 (A)
British asbestos imports from 1950 to 2000. 27–30 (B)
Imports of asbestos from the United States from 1956 to 2000.
30 methods the methods and results of the sample source MALCS case-control study have been described elsewhere.
During the period from 2001 to 2006, a telephone interview was conducted on the history of life-long career for 622 patients and 1420 control groups.
We also interviewed 420 patients with lung cancer who had been removed since 1940, and as a control group for lung load analysis, they were able to obtain lung samples.
Patients with lung cancer and melanoma determined by chest physician, lung cancer nurse specialist and hospital onset statistics (HES)
Notice from 170 hospitals in the UK.
1, 2 resection lung cancer provides the only sufficient source of national lung cancer samples that can be systematically identified, can be interviewed, and age distribution is similar to that of M.
Only a small percentage of all lung cancer is caused by asbestos, so the burden of asbestos lung cancer in this country sample reasonably represents the general population, except for a small number of people with a very heavy burden.
Obtaining written informed consent from 346 (77%)
A post-mortem sample analysis was performed in patients with interskin disease and their close relatives from 406 (96%)
Analysis of lung cancer patients with tissue resection.
Transmission electron microscope (TEM)
The samples were analyzed when the samples were available, and 133 samples of melanoma and 262 samples of lung cancer were analyzed.
Since 1940, all but 11 women with uterine fibroids born in 1925-1939 have been born.
The study was approved by the South Thames multi-center research ethics committee.
Professional classification title 1990 by standard professional classification (SOC 90)
And Standard Industrial Classification 1992 (SIC 92)
The code is grouped into the main work category.
Based on the proportion of deaths in all 16-74-year-olds from 1991 to 20003 in the UK, the mortality rate provides a basis for this classification.
1, 2 subjects were assigned to the highest-
The occupation of their work is ranked regardless of duration.
Table 3 shows the ORs previously reported for these categories 1.
Lung sample preparation and TEMLung sample anonymous and sent to Health and Safety Laboratory (HSL)
TEM count for asbestos fibers exceeding 5 µm (appendix 2).
Sensitivity of target analysis, 0. 01u2005mf/g (
Millions of fiber per gram)
, All but 2 are implemented.
Sample 8% (
2/133 cases of lung cancer and 9/262 cases of lung cancer).
The sensitivity was increased to 0.
For a subset of samples that initially counted five or less asbestos fibers, 003 u2005 mf/g.
For statistical analysis, see Annex 1.
Fitting the model to estimate and adjust the effect of using lung cancer as a control.
At a low dose, melanoma: lung cancer or a dose response that will reflect a real melanoma, but with an increase in the burden on the lungs, the downward curvature increases (
Figure 2 real line)
Increased proportion of lung cancer caused by asbestos.
The model was used to estimate the distribution of lung burden in British men born in 1945, thus calculating their burden as asbestos lung (
See footnote 2 for details).
This birth cohort is a good representation of our cases of intertumor as their average date of birth is September 1944.
1945 future age of birth cohortspecific death-
Unadjusted age and birth cohort analysis to estimate mortality rates in men in the UK for melanoma and lung cancerrates in 5-year age-groups (35–39 to 85–89)and periods (
1990-1994 to 2005-2009).
Our dose-response model is linear, so the age at which to predict the level of melanoma and excessive lung cancer-
In each lung burden category, the specific mortality rate is proportional to the average lung burden.
Lifetime risk (
Probability of death at 90)
Calculate the actuarial current of responsibility for each lung (2013)
All other causes of death in the UK.
These lifetime risks have been standardized to the estimated probability of death from a pre-90-year-old skin disease (0. 86%)
And lung cancer (4. 67%)
Of all British men born in 1945
Download the new tabDownload figureOpen powerpointFigure2 oral tonic salt for the hemangioma (
95% floating CIs)
In men who used resection of lung cancer as a control, asbestos lung load: the linear axis on the upper chart, the number axis on the lower chart.
When the risk of lung cancer caused by asbestos is ignored, the fitting degree of the linear model deteriorates significantly (p=0. 02; dashed line).
The main result is based on the total weight of asbestos fiber, regardless of the fiber type.
Logistic regression was used to estimate the interskin risk of asbestos with respect to Amistat, fitting the weighted sum of Amistat and amistin lung burden, ignoring other fiber types (
Only 7% of the count fibers)
And adjust the weight of asbestos: give the best-fitting model.
The methods and results of the sample-sourced MALCS case-control study have been described elsewhere.
During the period from 2001 to 2006, a telephone interview was conducted on the history of life-long career for 622 patients and 1420 control groups.
We also interviewed 420 patients with lung cancer who had been removed since 1940, and as a control group for lung load analysis, they were able to obtain lung samples.
Patients with lung cancer and melanoma determined by chest physician, lung cancer nurse specialist and hospital onset statistics (HES)
Notice from 170 hospitals in the UK.
1, 2 resection lung cancer provides the only sufficient source of national lung cancer samples that can be systematically identified, can be interviewed, and age distribution is similar to that of M.
Only a small percentage of all lung cancer is caused by asbestos, so the burden of asbestos lung cancer in this country sample reasonably represents the general population, except for a small number of people with a very heavy burden.
Obtaining written informed consent from 346 (77%)
A post-mortem sample analysis was performed in patients with interskin disease and their close relatives from 406 (96%)
Analysis of lung cancer patients with tissue resection.
Transmission electron microscope (TEM)
The samples were analyzed when the samples were available, and 133 samples of melanoma and 262 samples of lung cancer were analyzed.
Since 1940, all but 11 women with uterine fibroids born in 1925-1939 have been born.
The study was approved by the South Thames multi-center research ethics committee.
Professional classification title 1990 by standard professional classification (SOC 90)
And Standard Industrial Classification 1992 (SIC 92)
The code is grouped into the main work category.
Based on the proportion of deaths in all 16-74-year-olds from 1991 to 20003 in the UK, the mortality rate provides a basis for this classification.
1, 2 subjects were assigned to the highest-
The occupation of their work is ranked regardless of duration.
Table 3 shows the ORs previously reported for these categories 1.
Lung sample preparation and TEMLung sample anonymous and sent to Health and Safety Laboratory (HSL)
TEM count for asbestos fibers exceeding 5 µm (appendix 2).
Sensitivity of target analysis, 0. 01u2005mf/g (
Millions of fiber per gram)
, All but 2 are implemented.
Sample 8% (
2/133 cases of lung cancer and 9/262 cases of lung cancer).
The sensitivity was increased to 0.
For a subset of samples that initially counted five or less asbestos fibers, 003 u2005 mf/g.
For statistical analysis, see Annex 1.
Fitting the model to estimate and adjust the effect of using lung cancer as a control.
At a low dose, melanoma: lung cancer or a dose response that will reflect a real melanoma, but with an increase in the burden on the lungs, the downward curvature increases (
Figure 2 real line)
Increased proportion of lung cancer caused by asbestos.
The model was used to estimate the distribution of lung burden in British men born in 1945, thus calculating their burden as asbestos lung (
See footnote 2 for details).
This birth cohort is a good representation of our cases of intertumor as their average date of birth is September 1944.
1945 future age of birth cohortspecific death-
Unadjusted age and birth cohort analysis to estimate mortality rates in men in the UK for melanoma and lung cancerrates in 5-year age-groups (35–39 to 85–89)and periods (
1990-1994 to 2005-2009).
Our dose-response model is linear, so the age at which to predict the level of melanoma and excessive lung cancer-
In each lung burden category, the specific mortality rate is proportional to the average lung burden.
Lifetime risk (
Probability of death at 90)
Calculate the actuarial current of responsibility for each lung (2013)
All other causes of death in the UK.
These lifetime risks have been standardized to the estimated probability of death from a pre-90-year-old skin disease (0. 86%)
And lung cancer (4. 67%)
Of all British men born in 1945
Download the new tabDownload figureOpen powerpointFigure2 oral tonic salt for the hemangioma (
95% floating CIs)
In men who used resection of lung cancer as a control, asbestos lung load: the linear axis on the upper chart, the number axis on the lower chart.
When the risk of lung cancer caused by asbestos is ignored, the fitting degree of the linear model deteriorates significantly (p=0. 02; dashed line).
The main result is based on the total weight of asbestos fiber, regardless of the fiber type.
Logistic regression was used to estimate the interskin risk of asbestos with respect to Amistat, fitting the weighted sum of Amistat and amistin lung burden, ignoring other fiber types (
Only 7% of the count fibers)
And adjust the weight of asbestos: give the best-fitting model.
Results the dose response Table 1 of melanoma and lung cancer shows the distribution of the load of the lung of asbestos in squamous cell carcinoma and the removal of lung cancer.
Sum of estimated ORs for men and women (last row)
Adjusted to the period of birth (
1940-1944, 1945-1949, 1950-1954 and 1955)
And sex, although neither is important (p=0.
6 is sex, ptrend = 0.
5 during birth).
There are too few women analyzed separately, and there are further models --
The fitting room is limited to men only.
Figure 2 and Table 2 the reference group for the intermediate skin cell ORs is the lowest lung load category (20u2005µm.
The median width is 0. 09u2005µm (chrysotile), 0. 17u2005µm (crocidolite), 0. 30u2005µm (amosite), 0. 49u2005µm (tremolite), 0. 58u2005µm (anthophyllite)and 0. 61u2005µm (actinolite).
After stratification by fiber type, there was no significant association between disease status and fiber size.
Dose-Response Table 1 for melanoma and lung cancer shows the distribution of the lung load of asbestos in melanoma and removal of lung cancer.
Sum of estimated ORs for men and women (last row)
Adjusted to the period of birth (
1940-1944, 1945-1949, 1950-1954 and 1955)
And sex, although neither is important (p=0.
6 is sex, ptrend = 0.
5 during birth).
There are too few women analyzed separately, and there are further models --
The fitting room is limited to men only.
Figure 2 and Table 2 the reference group for the intermediate skin cell ORs is the lowest lung load category (20u2005µm.
The median width is 0. 09u2005µm (chrysotile), 0. 17u2005µm (crocidolite), 0. 30u2005µm (amosite), 0. 49u2005µm (tremolite), 0. 58u2005µm (anthophyllite)and 0. 61u2005µm (actinolite).
After stratification by fiber type, there was no significant association between disease status and fiber size.
Discussion of dose-response this is the first study to obtain career history through individual interviews and to measure the burden of asbestos lung in a large population by TEM
The basic series of patients with skin disease.
Our fitting model estimated and adjusted the effect of using lung cancer as a control.
Table 2 shows that this effect is small in men with a lung burden of less than 96%. 2u2005mf/g (
SMR 6u2005µm;
JC McDonald's and B Armstrong, personal communication).
For two reasons, however, we have not tried to adjust our data for elimination.
First of all, these people were born from 1940 and were mainly exposed during the end of the 1960 to late 1970 exposure at amocite, so they were exposed to similar mean intervals in lung samples.
Second, our lung samples were obtained after more than 20 years of cessation of exposure to a large number of angle flash rocks.
If, as suggested by Tossavainen et al, further removal of long-angle flash fibers would be minimal, further studies over the next decade should show a similar dose response.
However, a larger proportion of the inhaled fibers from recent environmental exposures will be retained, which is a bit exaggerated by the recent birth of people at the risk of melanoma predicted from the pulmonary burden of the angle flash rocks.
In contrast, in a dwell time model, early exposure leads to a higher risk of life, while late exposure means a higher dose-
Specific risks for young people, especially environmental exposure that may begin in childhood.
Environmental asbestos exposure our case-control analysis showed that 14% of men and 62% of women were not caused by occupational or family exposure to asbestos.
Only low men and women
6 of the 12 lung cancers in the risk occupation and 6 of the 60 lung cancers have a lung burden of more than 0. 05u2005mf/g (table 3).
Three of these six mesotheli tumors and one of the six lung cancers mentioned potential asbestos exposure at work (
Occasionally handle 1 of the sealed asbestos waste, 1 of the asbestos ironing boards used at work, 2 office staff of the company handling construction materials).
These potential exposures that are not classified as substantial when coding the history of these occupations indicate that about 25% (3/12)
Uterine fibroids with obvious low
The risk occupation may be due to this kind of work-
Related exposure.
Dose response this is the first study to obtain career history through individual interviews and to measure the burden of asbestos lung from a large population via TEM
The basic series of patients with skin disease.
Our fitting model estimated and adjusted the effect of using lung cancer as a control.
Table 2 shows that this effect is small in men with a lung burden of less than 96%. 2u2005mf/g (
SMR 6u2005µm;
JC McDonald's and B Armstrong, personal communication).
For two reasons, however, we have not tried to adjust our data for elimination.
First of all, these people were born from 1940 and were mainly exposed during the end of the 1960 to late 1970 exposure at amocite, so they were exposed to similar mean intervals in lung samples.
Second, our lung samples were obtained after more than 20 years of cessation of exposure to a large number of angle flash rocks.
If, as suggested by Tossavainen et al, further removal of long-angle flash fibers would be minimal, further studies over the next decade should show a similar dose response.
However, a larger proportion of the inhaled fibers from recent environmental exposures will be retained, which is a bit exaggerated by the recent birth of people at the risk of melanoma predicted from the pulmonary burden of the angle flash rocks.
In contrast, in a dwell time model, early exposure leads to a higher risk of life, while late exposure means a higher dose-
Specific risks for young people, especially environmental exposure that may begin in childhood.
Environmental asbestos exposure our case-control analysis showed that 14% of men and 62% of women were not caused by occupational or family exposure to asbestos.
Only low men and women
6 of the 12 lung cancers in the risk occupation and 6 of the 60 lung cancers have a lung burden of more than 0. 05u2005mf/g (table 3).
Three of these six mesotheli tumors and one of the six lung cancers mentioned potential asbestos exposure at work (
Occasionally handle 1 of the sealed asbestos waste, 1 of the asbestos ironing boards used at work, 2 office staff of the company handling construction materials).
These potential exposures that are not classified as substantial when coding the history of these occupations indicate that about 25% (3/12)
Uterine fibroids with obvious low
The risk occupation may be due to this kind of work-
Related exposure.
Conclusion our results confirm the primary contribution of armitette to the incidence of melanoma in the UK and the substantial contribution of non-melanoma
Occupational exposure to asbestos, especially for women.
1 the overall distribution of asbestos lung burden in British men born at the age of 1940 and the associated risk of melanoma and lung cancer are shown in Table 2.
Minimum exposure category ( 3:1 aspect ratio)
Length above 5 µm.
Length, width, diffraction pattern type and quantitative weight percentage oxide composition of energy dispersion X-
Ray analysis of each asbestos fiber found.
The count lasts until at least 30 asbestos fibers are identified or until 0.
1 mg skim dry lung was analyzed with a sensitivity of 0. 01u2005mf/g (
Millions of fiber per gram).
This sensitivity was not achieved in 2.
Sample 8% (
2/133 cases of lung cancer and 9/262 cases of lung cancer)
, Due to the low fiber concentration of the sample, but the high content of other inorganic particles, a lower filtration load is required, so a large area of the filter needs to be analyzed by TEM.
The sensitivity has tripled to 0.
003 u2005 mf/g later extended the selection of new equipment for TEM analysis, and the subgroup samples included the month-like female patients with M 26 m. who were born in 1940, there were 5 or less asbestos fibers originally counted.
The linear dose-response model in the I lung burden category has l (i)
Lung cancer d with average asbestos lung load (i)and m(i)mesotheliomas.
If the risk of melanoma and the relative risk of excessive lung cancer increase linearly with the increase of lung burden, the slope B of melanoma and the slope k of lung cancer, the expected ratio of melanoma to lung cancerbd(i)]/[1+kd(i)].
Slope B and k are estimated by maximum likelihood of log (odds)
, It is regarded as the error variance v with the normal distribution (i)=1/m(i)+1/l(i).
The Constant 1 Constant determines the size of the risk of melanoma (
Or lifetime risk or SMR).
The constant is set to the observation value of log [m(1)/l(1)], the log(odds)in the lowest (reference)
Exposure category, give the solid line in Figure 2.
ORs for each lung burden category (including the reference group) as shown in Figure 2, the log corresponds to the "floating absolute risk" CIs (odds)variances v(i).
25 with the first group as the reference group, the usual definition of the first group OR is (
Real odds for group 1)/(
Real odds for group 1.
The definition of floating OR is (
Real odds for group 1)/(
The odds observed in the first group).
The denominator observed in group 1 is a known zero variance constant, so the error variance of the log (floating OR)
The first class is equal to v (i)
, Variance of Log (odds).
The distribution of lung cancer burden in the general population and the corresponding lifetime risk of non-asbestos-induced lung cancer in the category I lung cancer burden is l (i)/(1+kd(i)).
We assume that the distribution of lung burden in the general population
Asbestos lung cancer, so the ratio p (i)
Among British men in the same birth cohort, the I lung burden category (
Born at about 1945)
The estimate in table 2 is: therefore, the average lung burden for men in this birth cohort is σ p (i)d(i).
Their expected death.
Based on the unadjusted age and birth cohort analysis, the mortality rate of M & M and lung cancer was calculated for each age of M & Mrates in 5-year age-groups (35–39 to 85–89)and periods (
1990-1994 to 2005-2009).
Male with average lung burden d (i)
These estimated rates are multiplied by Md (i)
Skin disease and L (1+kd(i))
Because of lung cancer
The risk of their life (
The probability of death of melanoma and lung cancer is 90 years old, respectively)
Then, assume the current (2013)
Rate of all other causes of death.
Constant M and L were adjusted to make the population average of these lifetime risks equal to the overall population forecast for lung cancer (4. 67%)
Skin Disease (0. 86%).
Comparison of asbestos and asbestos the effects of asbestos relative to asbestos are estimated in logistic model fitting log (
Lung burden of Amistat plus asbestos)
As a continuous variable, asbestos fiber is given weight w.
We fixed the offset using the estimated lung load coefficient k in the unweighted model to give the nested model and the likelihood-based CI for w.
For jth individuals with armite lung burden aj and medley lung burden cj, offset = log [m(1)/l(1)]−log(1+kdj).
The linear dose-response model in the I lung burden category has l (i)
Lung cancer d with average asbestos lung load (i)and m(i)mesotheliomas.
If the risk of melanoma and the relative risk of excessive lung cancer increase linearly with the increase of lung burden, the slope B of melanoma and the slope k of lung cancer, the expected ratio of melanoma to lung cancerbd(i)]/[1+kd(i)].
Slope B and k are estimated by maximum likelihood of log (odds)
, It is regarded as the error variance v with the normal distribution (i)=1/m(i)+1/l(i).
The Constant 1 Constant determines the size of the risk of melanoma (
Or lifetime risk or SMR).
The constant is set to the observation value of log [m(1)/l(1)], the log(odds)in the lowest (reference)
Exposure category, give the solid line in Figure 2.
ORs for each lung burden category (including the reference group) as shown in Figure 2, the log corresponds to the "floating absolute risk" CIs (odds)variances v(i).
25 with the first group as the reference group, the usual definition of the first group OR is (
Real odds for group 1)/(
Real odds for group 1.
The definition of floating OR is (
Real odds for group 1)/(
The odds observed in the first group).
The denominator observed in group 1 is a known zero variance constant, so the error variance of the log (floating OR)
The first class is equal to v (i)
, Variance of Log (odds).
The distribution of lung cancer burden in the general population and the corresponding lifetime risk of non-asbestos-induced lung cancer in the category I lung cancer burden is l (i)/(1+kd(i)).
We assume that the distribution of lung burden in the general population
Asbestos lung cancer, so the ratio p (i)
Among British men in the same birth cohort, the I lung burden category (
Born at about 1945)
The estimate in table 2 is: therefore, the average lung burden for men in this birth cohort is σ p (i)d(i).
Their expected death.
Based on the unadjusted age and birth cohort analysis, the mortality rate of M & M and lung cancer was calculated for each age of M & Mrates in 5-year age-groups (35–39 to 85–89)and periods (
1990-1994 to 2005-2009).
Male with average lung burden d (i)
These estimated rates are multiplied by Md (i)
Skin disease and L (1+kd(i))
Because of lung cancer
The risk of their life (
The probability of death of melanoma and lung cancer is 90 years old, respectively)
Then, assume the current (2013)
Rate of all other causes of death.
Constant M and L were adjusted to make the population average of these lifetime risks equal to the overall population forecast for lung cancer (4. 67%)
Skin Disease (0. 86%).
Comparison of asbestos and asbestos the effects of asbestos relative to asbestos are estimated in logistic model fitting log (
Lung burden of Amistat plus asbestos)
As a continuous variable, asbestos fiber is given weight w.
We fixed the offset using the estimated lung load coefficient k in the unweighted model to give the nested model and the likelihood-based CI for w.
For jth individuals with armite lung burden aj and medley lung burden cj, offset = log [m(1)/l(1)]−log(1+kdj).
Appendix 2: preparation of lung samples and transmission electron microscopy all lung tissue samples were sent to the pathology laboratory in Leeds for preliminary evaluation of their applicability.
Microcut thin tissue slices from wax blocks for further evaluation before removing wax blocks
Wax in PX, wash in ether, micro-cut to remove cancer and fiber tissue.
Then send the sample anonymously to the Health and Safety Laboratory (HSL)
For quantitative transmission electron microscopy (TEM)analysis.
In HSL, take representative samples from the supplied tissue and cut them into cubes (
About 3mm edges)
Dry overnight in a vacuum cleaner and then weigh to get dry weight.
The tissue is then digested with bleach, and the equal sample is filtered onto the membrane filter.
The filter with the maximum aliquot has been grayed out overnight in the low temperature crusher under control conditions to further remove the organic material.
The residue after ashing is re-suspended in water, and a series of equal samples are filtered onto 0.
A polycarbonate filter with a pore diameter of 2 m.
When dry, the strip of the final filter is coated with carbon, partially cut and transferred to the 200 mesh nickel index grid.
Several grids of each filter are prepared by dissolving polycarbonate on a filter paper soaked with a 20% 1,2-mixture
1-diammonium and 80%methyl-2 -pyrrolidone.
This leaves a thin layer of carbon film that supports particles on the grid.
New disposable containers and filtration equipment are used for each sample to avoid any crossover
Pollution and process gaps are run for each batch of analysis.
The prepared TEM grids were analyzed in the FEI CM12 TEM equipped with EDAX Inc be window energy dispersion X-ray detector.
Scan the mesh opening on the fluorescent screen at 11 k magnification to identify the fiber (
Particles with parallel edges and> 3:1 aspect ratio)
Length over 5 m.
Length, width, diffraction pattern type and quantitative weight percentage oxide composition of energy dispersion X-
Ray analysis of each asbestos fiber found.
The count lasts until at least 30 asbestos fibers are identified or until 0.
1 mg skim dry lung was analyzed with a sensitivity of 0. 01u2005mf/g (
Millions of fiber per gram).
This sensitivity was not achieved in 2.
Sample 8% (
2/133 cases of lung cancer and 9/262 cases of lung cancer)
, Due to the low fiber concentration of the sample, but the high content of other inorganic particles, a lower filtration load is required, so a large area of the filter needs to be analyzed by TEM.
The sensitivity has tripled to 0.
003 u2005 mf/g later extended the selection of new equipment for TEM analysis, and the subgroup samples included the month-like female patients with M 26 m. who were born in 1940, there were 5 or less asbestos fibers originally counted.
References skerake C, Gilham C, incubation. . . , et al.
Occupational, family, and environmental cancer risk in the UK population: case-control study.
Cancer 2009; 100:1175–83. doi:10. 1038/sj. bjc.
6604879. Science alimpeto openurlcrossrefpmedweb J, rake, Gilham C, etc. et al.
Risk of occupational, family, and environmental melanoma in the UK: case-control study.
Mcelvenny DM, Darnton AJ, price MJ, etc.
From 1968 to 2001, there was a mortality rate in the United Kingdom. Occup Med (Lond)2005; 55:79–87. doi:10.
1093/occmed/kqi034OpenUrlAbs
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