Asbestos are crystallized silicate minerals that form fibers with different structures and characteristics. Asbestos fibers are very durable and can tolerate very high temperatures. Therefore it was common to use asbestos as a fire retardants, heat insulation and where high temperature is used. Asbestos has been banned in Iceland from 1983 but can still be found in large amounts in buildings, ships and hot water pipes. Large amounts of asbestos were imported in the years before the ban but diminished soon to almost nothing today. Needle or filamentous shaped dust is released when working with asbestos. It is this dust that is dangerous for health. The latent time from exposure to disease can be up to forty years. Asbestos reaches the lungs via inhalation and can cause asbestosis that is a form of lung fibrosis with slow progression. Asbestos can also cause benign pleural effusions, pleural plaques and diffuse pleural thickening. Asbestos is a carcinogen. Lung cancer is most common but asbestos is also a risk factor for cancers of other organs. Mesothelioma is most common in the pleura but can be seen in other membranes. The incidence of these tumors is high in Iceland and is still increasing among males. Of all the European countries mortality is highest in Iceland. It is important for physicians to include asbestos exposure in the differential diagnosis of lung diseases and when lung cancer is diagnosed.

Figure 1: Asbestimport to Iceland by years in tons

Figure 2: CT scan of the chest showing asbestos changes. Shown are calcified pleural plaques, pleural effusion and lung fibrosis.

Figure 3: CT scan of the chest. Shown are calcified pleural plaques

Figure 4: Needle bispsy from thickened pleura, composed of acellular, collagenrich fibrotic tissue that diffusely forms parallel bundles

Figure 5: CT scan of the chest showing enclosing irregular soft tissue thickening on the chest wall- and mediastinal pleura typical for mesothelioma.

Table I. Asbestos related diseases

Disease	Organ	Diagnosis
Asbestosis	Lung interstitium	Medical imaging, tissue sample
Benign pleural effusion	Pleural cavity	Fluid analysis, medical imaging
Pleural plaques/pleural thickening	Parietal pleura	Medical imaging
Mesothelioma of pleura	Pleura	Tissue sample
Lung cancer	Lung tissue	Tissue sample
Mesothelioma of peritoneum	Peritoneum	Medical imaging, tissue sample
Other cancers	Various	Tissue sample

Table II. Number of malignant mesothelioma cases in ten years periods by gender, annual incidence per million, and 95 % confidence interval (CI)

		1965-1974	1975-1984	1985-1994	1995-2004	2005-2014
Males	Number of cases	1	4	9	19	27
	Incidence per million inhabitants	1,4	4,8	9,4	17,6	21,4
	95% CI	0,1-7,1	1,5-11,6	4,6-17,2	10,9-26,9	14,4-30,7
Females	Number of cases	2	0	3	4	7
	Incidence per million inhabitants	2,9	-	3,1	3,7	5,6
	95% CI	0,5-9,6	-	0,8-8,5	1,2-8,8	2,4-11,0

CI: confidence interval

Table III. Number of malignant mesothelioma cases and deaths by age categories, and gender

		<50	50-59	60-69	70-79	>80	Samtals
Males	Number of cases	3	8	16	20	13	60
Females	Number of cases	2	1	4	5	4	16
Males	Number deceased	1	5	7	18	11	42
Females	Number deceased	0	0	4	4	2	10

Table IV. Number of incident cases of malignant mesothelioma in ten years periods, and relative risk (RR) and 95 % confidence intervals (CI) during 1965 to 2014 among men and women, first period is the reference

		Number of cases	Relative risk	95% CI
Males	1965-1974	1	Reference
	1975-1984	4	3,34	0,37-29,84
	1985-1994	9	6,53	0,83-51,57
	1995-2004	19	12,24	1,64-91,39
	2005-2014	27	14,90	2,03-109,7
	Trend, p-value <,000
Females	1965-1974	2	Reference
	1975-1984	0	-
	1985-1994	3	1,07	0,18-6,43
	1995-2004	4	1,26	0,23-6,89
	2005-2014	7	1,92	0,40-9,22
	Trend, p-value 0,11

CI: confidence interval

Table V

Country	Age corrected mortality per million inhabitants for the years 1994 til 2010 in several European countries for mesothelioma and asbestosis (number of years that are foundation for incidence)*
	Mesothelioma	Asbestosis
Danmark	8.87 (13)	1.91 (13)
Finnland	8.96 (15)	2.39 (15)
France	7.74 (10)	0.79 (10)
Germany	7.04 (13)	0.71 (13)
Iceland	24.58 (13)	4.59 (2)
Netherlands	15.91 (15)	0.49 (15)
Norway	7.99 (15)	2.07 (15)
Sweden	7.65 (14)	0.60 (14)
England	18.36 (11)	1.16 (11)

*This table is a simplification of a table from reference 45