ABSTRACT
In this paper, 177 cases of artificial stone-related silicosis in interior decoration workers from Israel, Spain, USA, Italy and Australia were analyzed. Interior decoration workers were from small businesses (or workshops), engaged in kitchen and/or bathroom artificial stone countertops cutting, grinding, polishing and other reprocessing. In the working environment, the content of crystalline silica in artificial stone was more than 70%, and the concentration of silica dust exceeded the relevant standards. Most workplaces used dry cutting without ventilation and dust removal and other dust-proof measures, and most workers did not wear qualified respiratory protective equipment. Taking comprehensive measures such as wet operation, ventilation and dust removal, and individual protection can effectively prevent the occurrence of artificial stone-related silicosis.
ABSTRACT
<p><b>OBJECTIVE</b>To study the changes of nitric oxide(NO) and nitric-oxide synthase(NOS) in the development of cold-induced hypertension (CIH).</p><p><b>METHODS</b>Sixty male Sprague-Dawley adult rats were used. Thirty were exposed to cold (4 +/- 1) degrees C as cold-treated group while the other 30 were at (25 +/- 1) degrees C as controls, 4 hours a day for 6 weeks for both groups. Systolic blood pressure (SBP) and heart rate were measured twice every week. Each group was further subdivided into three groups, 10 rats each. A subgroup of the cold-treated and control rats were sacrificed at 2, 4 and 6 week. Plasma was saved to measure superoxide dismutase (SOD) and malondiadehycle (MDA), while heart was homogenated to measure NO, NOS.</p><p><b>RESULTS</b>1 SBP increased during 6 weeks of exposure to cold. From the second week, SBP of cold-treated group [(94.16 +/- 3.81) mm Hg] was significantly greater than that of control group [(88.77 +/- 4.45 mm Hg), P<0.01]. The highest SBP level was achieved at the sixth week [(116.78 +/- 3.79)mm Hg, P<0.01]. 2 Compared to the control group, SOD in cold-treated group decreased significantly from the second week, and maintained throughout the time of exposure to cold (P<0.05). MDA levels did not differ significantly between cold-treated and control groups though it increased mildly during 6 weeks of cold exposure (P>0.05). Heart NOS in cold-treated group decreased significantly from the fourth week to the sixth week. And a mild decrease was observed in heart NO of cold-treated group during 6 weeks of exposure (P>0.05).</p><p><b>CONCLUSION</b>Cold-induced hypertension is induced in rats after repeated exposure to cold. The levels of NOS, NO decrease accordingly to the rise of blood pressure. This indicates that the dysfunction of NO and NOS is involved in the development of CIH.</p>
Subject(s)
Animals , Male , Rats , Cold Temperature , Disease Models, Animal , Hypertension , Metabolism , Malondialdehyde , Blood , Nitric Oxide , Metabolism , Nitric Oxide Synthase , Metabolism , Rats, Sprague-Dawley , Superoxide Dismutase , BloodABSTRACT
Objective To observe the effect of relative humidity on indoor concentrations of formaldehyde and ammonia. Methods 12 currently decorated rooms were randomly divided into 3 groups, 4 rooms involved in each, in which the average relative humidity of rooms were 55%,65% and 75% respectively. The concentrations of formaldehyde, ammonia were monitored every two days for 9 consecutive days according to GB/T18204.26 -2000 and GB/T18204.25-2000. Results The concentrations of formaldehyde and ammonia decreased gradually with the prolongation of the experimental period. The concentrations of formaldehyde in the rooms of 55%,65% and 75% relative humidity groups decreased significantly after the 5th, 3rd, 3rd day of the experiment compared with those in the same group at the 1st day of the experiment respectively(P