Environmental health sciences education--a tool for achieving environmental equity and protecting children.

Children are highly susceptible to deleterious effects of environmental toxins. Those who live in underserved communities may be particularly at risk because environmental pollution has been found to be disproportionately distributed among communities. Mounting evidence suggests that asthma rates are rising and that this disease can be caused or aggravated by air pollution. Although ambient air quality has generally improved, these improvements have not reached minority communities in equal proportions. This and other data has fueled the concept of environmental justice or environmental equity, which has led to community activism and government actions. One possible example of environmental inequity and its consequences is the Hunt's Point community, in the South Bronx, New York. This community experiences a high pollution burden with the siting of facilities that emit hazardous wastes into the air. Our approach to this problem has been the formation of mechanisms for bidirectional communication between community residents, government entities, and academic institutions such as Mount Sinai Medical Center. As a result of this experience, we believe that the key to achieving environmental health, especially in communities of color where many children are at risk, is to empower residents to take charge of their environment by providing relevant educational opportunities. Strategies for environmental health education include multitiered training approaches that include community residents, parent education, direct children education, and community education through professional counselors and train-the-trainer approaches. We propose that academic researchers must use community residents not just as subjects of our studies, but to increase our mutual understanding of environmental health, resulting in active participation of community members in research design, data collection, analysis, and dissemination of results in order to make intervention strategies more effective.

Tin in the thymus gland of dogs.

The thymus glands from four mixed breed dogs were analyzed to determine the water content, chloroform extractable fraction and residue. The thymi samples were assayed for tin and compared to the tin in the spleen and muscle tissue. The tin content in the thymus gland (29.4 ppm) was higher than the muscle (14.9 ppm) or spleen (12.8 ppm). The tin content in the lipid portion of the thymus was approximately four times greater than the non-chloroform extractable fraction (primarily protein).

Tin concentration in the thymus glands of rats and mice and its relation to the involution of the gland.

Tin is an ubiquitous element and thus enters mammals through the food chain. It has never been found to be dysfunctional in either plants or animal tissue and has been regarded as an innocuous background material. Of the many organs and glands that have been analyzed for tin, only the thymus gland exhibits an above average value for tin. A complete study on the tin content in the thymus gland has never been published and this work is an attempt to investigate this subject. Three types of rodents were used in this study; inbred Lewis rats, inbred A/KI mice (a breast cancer prone mouse) and outbred COBS mice (a cancer resistant mouse). The tin analysis of the muscle, spleen, and thymus indicated constant values for the muscle and spleen tissue, but an increase in the thymic tin concentration (ppm) with age. Besides normal aging studies, the animals were administered the disodium salt of dexamethasone-21-phosphate (dexa), which causes rapid loss of lymphocytes from the spleen and thymus but has no effect upon the muscle. Tin concentration in the muscles remained constant, showed a loss from the spleen and an increase in the thymus gland. The increase indicates that the tin was probably located in the medulla of the thymus, which may be the active biochemical site for tin in rodents. When compared to the COBS mice, the A/KI mice showed a non-statistical difference in tin content in the muscle and spleen and statistically significant lower tin content in the thymus gland.

Organotin implications in anticarcinogenesis. Background and thymus involvement.

A comprehensive study of the scientific literature regarding tin content in normal and pathogenic human tissue has disclosed that various organotin materials retard both the onset and growth of cancer in laboratory animals, and decreased tissue tin in humans may be associated with tumour development. Initial studies by the authors have shown that the thymus gland of the mouse possesses a relatively high concentration of tin and is also the major site of accumulation for 14C-labelled tri-n-butyltin fluoride (TBTF). When mammary cancer-prone mice with transplanted tumours were orally dosed continuously with this agent in their drinking water, the tumour growth rate was significantly reduced. Both mouse mammary tumours and human lung tumours show low tin content compared to normal body tissue.

Kinetic determination of phenols by a fixed-time method.

The fixed-time kinetic method is used for the determination of 15 phenols in methanol and acetic acid by measurement of the yellow products from the oxidation of the phenols with sodium metaperiodate. An increase in acid and metaperiodate concentrations enhances the rate of reaction, whereas the use of 2-propanol as the solvent decreases it.

A modified phenylfluorone method for determining organotin compounds in the ppb and sub-ppb range.

The phenylfluorone method for tin analysis has been modified to be specific for organotin samples in the ppb and sub-ppb range (4-.1 micrograms of tin). Two extractions of an aqueous solution containing bis (tri-n-butyltin) oxide (TBTO) and tin sulfate yield results which are quantitative for TBTO without interference from the tin sulfate. The extracts are wet oxidized with hydrogen peroxide and sulfuric acid. The tin is determined from its lambda max near 530 nm through its complex with 2,6,7-trihydroxy-9-phenylisoxanthane-3-one (phenylfluorone) in the presence of cetyltrimethylammonium bromide. A Beer Lambert plot is obtained in the range of 0.1 to 7.0 micrograms of tin/sample with slope of 0.0344 with a correlation coefficient of greater than 0.990. The method has been successfully used to analyze over 400 environmental samples.