vree from. Their work can help authorities track down the sources of specific types of problem pollution in afflicted areas, especially large cities. To understand.pollution’s effects on people and their environment, studies are needed on ‘‘the places where it (pollution) all gets mixed together and where people are ex- posed to it,’’ says Dr. R. Jervis, professor of Nuclear Chemistry at the University of Toronto. Previous studies, including those done by the Ministry of Environment, have tended to focus on the pollution’s _ sources (factory stacks, etc.), but not on the areas in which the pollution ends up, he adds. Dr. Jervis and his colleagues have just completed studies on air and soil samples from three locations around metro Toronto: - Port Credit, the Toronto Islands and East Riverdale. The three areas have different amounts of traffic and industry and provide a cross- section of areas where different pollutants predominate. ara Port Credit has light industry and is mostly residential; Riverdale has heavy metal industry; and the Toronto Islands are purely residen- tial but receive LRT (long range transport) pollutants from Rochester and Hamilton, Dr. Jervis says. Most methods for finding pollution levels identify the general pollutants but give no indication of where they come from. For exam- ple, there are several types of sour- ces for lead pollution, such as lead smelters, automobiles and soil that has been contaminated. The source of a particular pollutant- can be identified by looking at factors such as the com- position of the pollutant (ie. whether it contains lead, copper, arsenic, etc.) and how big the par- ticles are. Particle sizes are in fact good predictors of the type of source, Dr. Jervis says. - The size of a pollution particle tells researchers what type of process the substance has been through. For example, particles of lead less than one-half of a millionth of a metre (0.5 micron) in size are the result of combustion processes (usually in automobiles) in which the substance has condensed from a very hot gas. They are very light and can travel great distances. Large particles (at least 1 micron) would be ‘‘things that come from grinding and general dust’’ often found around construction sites, Dr. Jervis explains. They are heavy, Teenage ‘angels’ can turn into killers By Carolyn Hoskins Roughly 50 per cent of juvenile murderers mask their growing hostility by behaving in an ex- tremely well-behaved conformist manner until their suppressed feelings explode in violence, a Toronto psychiatrist has found. Dr. Clive Chamberlain, Psychiatrist-in-Chief at the Thistletown Regional Centre for Young Offenders in Toronto, has coined the term ‘angelism’ to describe this virtually unrecognized_ clinical syndrome. He says it has emerged as a pattern in his 14 years of working with juvenile killers. About half of the 27 young mur- derers he has treated have shown some or all of the characteristics of this syndrome, for which there is no traditional psychiatric label, he says. His sample of 27 is one of the largest ever studied by a single psychiatrist in North America. Dr. Chamberlain says that there has been a steady incidence of juvenile murders throughout this century of about two per year. In- volving children age 16 and under, - such murders are about 100 times less common than suicide in this age group. Dr. Chamberlain says the ‘angelic’ children are completely out of touch with their primitive selves. ‘ ‘A healthy person is a blend of the selfish and altruistic,”’ he says. “Children with ‘angelism’ have suppressed any ability to know their innate needs. They smile when somebody insults them.” In his practice, Dr. Chamberlain sees many hostile, badly behaved teenagers, but ‘‘they are in touch with their feelings,’’ he says. But ‘angelic’ children, when the angelic facade bursts and they lash out and destroy, are usually sur- prised and horrified at their deeds. Dr. Chamberlain has identified a similar pattern in about 50 per cent of youthful arsonists and sex- offenders over the age of 12. These 50 per cent of these offenders are over-conforming and excessively anxious to please. Dr. Chamberlain says that the ‘angels’ try to act out their sup- pressed emotions by reading enor- mous amounts of science fiction or becoming absorbed in fantasy games like ‘‘Dungeons and Dragons.”’ : Rather than being harmful, these activities can act as psychological safety valves and may be therapeutic for this type of child, he says. ‘‘Even chess could fall into this category,’’ he adds. Dr. Chamberlain’s experiences have convinced him that these children are treatable and can become useful members of society. However, he is concerned about the limited treatment options available. Under the current Young Offen- ders Act, a youthful offender can be sentenced to a maximum of three years. This may not be enough time for proper treatment and rehabilitation. However, if a petition is made for the child to be tried as an adult, the maximum is 25 years—but the child may then be confined in an adult institution. There should be more flexibility in the system, Dr. Chamberlain says. He would like to see an in- determinate sentence possible in juvenile court, or perhaps a six-year maximum sentence with reviews, allowing’ sufficient time for treat- ment while still treating the offen- der as a juvenile. Sending 14 or 15 year-old children to an adult institution is ““grossly inappropriate,’’ he says. (Canadian Science News) don’t often travel far and are usually responsible for local pollution. Middle-sized particles often result from processes such as the casting of non-ferrous (non-iron) products, such as automobile wheels. Middle-sized particles present the greatest danger to health, since they are easily inhaled and are carried to the lower respiratory regions where they stick, Dr. Jervis says. (Many smaller particles are breathed out again.) Particles from different sources are also fingerprinted by the presence of other substances. Lead particles from automobiles are not only small, but also contain traces of bromine, zinc and maganese. Lead from factories is often associated with arsenic and antimony. In the U of T tests, air and soil samples are picked up by a vacuum-cleaner device and sucked onto. paper filters. The filters, in turn, are placed into a nuclear reac- tor where the particles become radioactive and give off energy that can be measured by a gamma ray spectrometer. The energy that each component of the particle (eg. cop- per, lead, etc.) gives off corres- ponds to a particular value that identifies what the substance is. The overall process is called ‘ac- tivation analysis’ and can be fine- tuned even further to determine just how much of each element is present in a sample. In the study, the researchers have been able to identify the main causes of pollution in the three Toronto areas. Samples from East Riverdale pointed to six dominant sources: automobiles, lead refinery, incinerators, oil and coal com- bustion, and in some places, wind- stirred dust. About 24 per cent of Nuclear reactor is used to ‘fingerprint’ pollutants By Pippa B. Wysong Scientists at the University of _ Toronto have been using a nuclear reactor to ‘‘fingerprint’’ pollutants and determine where they come ‘the lead in. the area comes from traffic, while close to 35 per cent comes from lead refineries. Dr. Jervis is now looking at samples taken from Queen’s Park in the heart of downtown Toronto. So far, results show the downtown is more polluted than residential Port Credit but considerably less polluted than East Riverdale. Three dominant types of down- town -pollution have been iden- tified—mostly combustion and in- cineration processes. One main source, not surprisingly, is automobile traffic, while another is probably garbage incineration. The Queen’s Park study is not yet com- plete. Dr. Jervis’ research has been supported by grants from the Natural Sciences and Engineering Research Coucil and the Ontario Ministry of Environment. (Canadian Science News) Seeking thallium to find gold By John Michell A novel approach to prospecting for gold has been found by a professor of geological science at the University of British Columbia. Dr. Harry V. Warren has shown that the presence of the metal thallium in the leaves of young trees, such as Douglas fir, spruce and pine, is a strong indication that an ore body containing gold may be buried below. Extensive tests have shown that thallium is always found along with gold in the leaves of trees growing in gold-containing soil. The amount of thallium in the leaves is close to ten times that of the gold; thallium can therefore be considered as a “‘pathfinder’’ for gold. Thallium is a metal with few commercial uses, since in many forms it is toxic to animals and people. However, the natural form Dr. Warren is tracing is not toxic to plants. This is the latest development in a study that began 40 years ago when Dr. Warren first entered the field of ‘‘biogeochemistry’’—the science concerned with the effect of soil chemicals on_ biological materials. Biogeochemical prospec- ting has become a practical tool in the search for ore bodies that may be buried under several metres of topsoil. The ore may be dissolved out of the bedrock by groundwater, or may be present in the soil because the latter is derived from the bedrock. All plants obtain minor amounts of elements from the soil in which they grow. Once traces of ore are in the soil, plants absorb them, along with water and other nutrients, through their roots. Indications of the probable presence of important metals in a mineralized area can be obtained rapidly and easily, since all that is required for analysis is a small sample of leaves or stems from plants growing above it. When an unusually large propor- tion of a metal is found in plant samples in a given area(about 1000 times the ‘base level’ for other plant samples taken near the same area), it’s a good indication that a major source of the metal lies beneath. In 1982, Dr. Warren found ab- normally large quantities of valuable metals in samples taken from fir and pine trees at a number of locations in the Pinchi fault, a massive fracture in the Earth’s crust extending from the Yukon border almost to Kamloops, B.C. Producing mines are frequently located in geological faults; for example, a major mercury mine is in the Pinchi fault. Dr. Warren’s work identified three locations within the Pinchi -fault in which leaf samples con- tained exceptionally high propor- tions of gold; in two locations the samples contained significant quan- tities of silver; and, in ten locations, samples contained unusually large quantities of mer- cury. These results justify further geological exploration, Dr. Warren says. 5 “I can point to no mines as yet, but I can point to the fact that several prospectors have followed up our findings and have already staked claims,’’ says Dr. Warren. Important ore bodies have been found throughout the world by biogeochemical prospecting, he ad- ded. In the United States, a num- ber of uranium deposits have been found in this’way. : The preferred method of analyzing the plant samples is ‘atomic absorption spectroscopy’, an extremely sensitive technique that can detect gold, thallium and other metals in minute quan- tities—parts per billion. Dr. Warren’s colleague, Stanya Hor- sky, has found that the method is so sensitive and accurate that sam- ples of dry, powdered, plant material weighing no more than one gram (about one half teaspoon) are enough to provide reliable results. : Professor Warren’s work has been supported by the Science Council of British Columbia and the Natural Sciences and Engineering Research Council. Ad- ditional funding was provided by the Geological Survey of Canada and Cominco Limited. (Canadian Science News) Device tests plant seedlings’ health Fluorometer for assessing the viability of tree seedlings. Seedling, enclosed in split globe (left) is given flash of light that makes it photosynthesize. Device measures seedling’s reaction. (Photo: ENSC Student Enterprises, SFU)