This page contains a Flash digital edition of a book.
Industry  Environment


millions of people worldwide, especially in Bangladesh and India, are exposed to elevated levels of arsenic in drinking water from wells tapping groundwater in young sediments. Chronic exposure to arsenic causes arsenicosis and increases the risk of a range of unpleasant skin and bladder cancers. Exposure is not restricted to the developing world; many areas of North America have groundwater with elevated arsenic levels that must be treated before distribution.


Antimony is also highly toxic, but compared to arsenic, it has lower mobility and bioavailability. As stibnite (Sb2


) is often an accessory mineral in lead and zinc ores, smelting is the primary source of anthropogenic releases into the environment. A recent health concern has been from the leaching of antimony from polyethylene terephthalate (PET) water bottles; antimony is used as a catalyst in the manufacture of some PET. Japan has banned the use of this type of PET for food packaging.


S3


VI: selenium and tellurium Selenium is an unusual element in that it is an essential element at low concentrations, but toxic at marginally higher levels so that the safe range of daily intake is relatively narrow (40 µg – 400 µg day-1


). This is in


contrast with other essential elements such as copper, which has a tolerable range over six orders of magnitude. Health effects can be correlated to low amounts of dietary selenium (Keshan disease and Kashin-Beck disease) or excessive selenium in drinking water (selenosis), with livestock particularly vulnerable[10]. However, there is evidence that selenium might mitigate the toxicity of mercury and minimise the risk of eating fish as a staple food source within at-risk populations.


Summary


Compound semiconductor wafer processing poses a low risk to the health of fab workers, provided they are properly handled and their processing waste is


disposed off according to local regulations. The elements that make up these compounds have a significant environmental impact and are recognised as priority pollutants in water resources, largely as a result of past industrial land uses such as mining. There is a growing awareness of the potential health impacts from these metals and various international groups are working on proposals to minimise the discharge and use of some of these elements, especially mercury. Although the semiconductor industry is responsible for only a very small fraction of these releases, pending environmental agreements may restrict the future use of some semiconductor materials.


© 2012 Angel Business Communications. Permission required.


References [1] Health & Safety Executive (2010),‘Report by the Health and Safety Executive on the control and Management of Hazardous Substances in Semiconductor Manufacturers in Great Britain in 2009. [2] http://eur-lex.europa.eu/LexUriServ/LexUriServ


’,Technical Report,Health and Safety Executive. .do?uri=CELEX:32006L0012:EN:NOT


[3] K.Torrance et al Semiconductor Today 4(4),66 - 68. [4] M.Veiga et al.(2004).Protocols for Environmental and Health Assessment of Mercury Released by Artisanal and Small Scale Miners, Report to the Global Mercury Project: Removal of Barriers to Introduction of Cleaner Artisanal Gold Mining and Extraction.


[5] R.Philipp et al.International Journal of Epidemiology 11257 (1982) [6] P


.Elliot et al.Occupational and Environmental Medicine 59,13 (2002),


[7] T.Laten et al.Brain Research Bulletin.55187 (2001) [8] J.Emsley The 13th Element.New York : John Wiley and Sons (2000) [9] ATSDR (2010) Medical Management Guidelines for Arsenic Trioxide.http://www.atsdr.cdc.gov/mhmi/mmg168.ht [10] R.Fosdyce (2005) Selenium Deficiency and Toxicity in the Environment.In: Selinus,O.et al.(eds.) Essentials of Medical Geology Amsterdam : Elsevier.417 – 433.


Table 1. Summary of main


compound semiconductor elements and possible health risks


.


January/February 2012 www.compoundsemiconductor.net 51


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112  |  Page 113  |  Page 114  |  Page 115  |  Page 116  |  Page 117  |  Page 118  |  Page 119  |  Page 120  |  Page 121  |  Page 122  |  Page 123  |  Page 124  |  Page 125  |  Page 126  |  Page 127  |  Page 128  |  Page 129  |  Page 130  |  Page 131  |  Page 132  |  Page 133  |  Page 134  |  Page 135  |  Page 136  |  Page 137  |  Page 138  |  Page 139  |  Page 140  |  Page 141  |  Page 142  |  Page 143  |  Page 144  |  Page 145  |  Page 146  |  Page 147  |  Page 148  |  Page 149  |  Page 150  |  Page 151  |  Page 152  |  Page 153  |  Page 154  |  Page 155  |  Page 156  |  Page 157  |  Page 158  |  Page 159  |  Page 160  |  Page 161  |  Page 162  |  Page 163  |  Page 164  |  Page 165  |  Page 166  |  Page 167  |  Page 168  |  Page 169  |  Page 170  |  Page 171  |  Page 172  |  Page 173  |  Page 174  |  Page 175  |  Page 176  |  Page 177  |  Page 178  |  Page 179  |  Page 180  |  Page 181  |  Page 182  |  Page 183  |  Page 184  |  Page 185  |  Page 186  |  Page 187  |  Page 188  |  Page 189  |  Page 190  |  Page 191  |  Page 192  |  Page 193  |  Page 194  |  Page 195  |  Page 196  |  Page 197  |  Page 198  |  Page 199  |  Page 200  |  Page 201  |  Page 202  |  Page 203  |  Page 204  |  Page 205  |  Page 206  |  Page 207  |  Page 208  |  Page 209  |  Page 210  |  Page 211  |  Page 212  |  Page 213  |  Page 214  |  Page 215  |  Page 216  |  Page 217  |  Page 218  |  Page 219  |  Page 220  |  Page 221  |  Page 222  |  Page 223  |  Page 224  |  Page 225  |  Page 226  |  Page 227  |  Page 228  |  Page 229  |  Page 230  |  Page 231  |  Page 232  |  Page 233  |  Page 234  |  Page 235  |  Page 236  |  Page 237  |  Page 238  |  Page 239  |  Page 240  |  Page 241