Encyclopedia of Environmental Science and Engineering, Volume I and II

376 EPIDEMIOLOGY much of the last century (but attaining much higher fi gures in some years) down to below 10 in many countries ...

EPIDEMIOLOGY 377 COHORT ANALYSIS OF MORTALITY A similar breakdown of age-specifi c mortality rates can be made, in order to reve ...

378 EPIDEMIOLOGY disease occurrence between the two sexes. Most when exam- ining these data would suggest that even though the d ...

EPIDEMIOLOGY 379 disease by age and sex, but by ethnic group as well. These differences in Table 2 illustrate the importance of ...

380 EPIDEMIOLOGY population. This provides information on the distribution of the disease and possibly allocation of resources i ...

EPIDEMIOLOGY 381 provide important information on carcinogenic hazards in the area to which it refers. The different proportions ...

382 EPIDEMIOLOGY to fi nd higher rates of colon cancer among those consum- ing more than the average. But this information we do ...

EPIDEMIOLOGY 383 among the workers exposed to the putative causative factor, whether that is a substance or a process that is us ...

384 EPIDEMIOLOGY in association with the presence of the disease, and less so with its absence. A case-control investigation led ...

EPIDEMIOLOGY 385 stratum, so that the trial is described as stratifi ed. An exam- ple may be the stage of disease (if distinct s ...

386 EPIDEMIOLOGY are found with the leukemias and lymphomas, and the longer with solid tumors. Often this long period of latency ...

EPIDEMIOLOGY 387 in life tables (RMLT), the name given to it by the originator, D. R. Cox, or as the proportional-hazards model. ...

388 EPIDEMIOLOGY McMichael A.J. (1976). Standardized mortality ratios and the health worker effect: scratching beneath the surfa ...

389 EUTROPHICATION INTRODUCTION For a considerable time, scientists have been aware of the natural aging of lakes, a process so ...

390 EUTROPHICATION and due to their swimming ability they are frequently found in rapidly moving streams. Some of the common gre ...

EUTROPHICATION 391 47 species of algae condensed from a list of 500 prepared from reports of more than 50 workers, as being repr ...

392 EUTROPHICATION shallow water prevents depth-dwelling algae from escaping the intensity of the sunlight penetration. Often mu ...

EUTROPHICATION 393 by salt-brine wastes, may destroy most of the algae present, however. Certain fresh-water algae may become ad ...

394 EUTROPHICATION The following are the most common sources of nitrogen and phosphorus in bodies of water: 1) Rainfall—Based on ...

EUTROPHICATION 395 we are taking out, and much of this excess ultimately gets washed out into our waterways. 7) Municipal Water ...