Mapping toxin exposure risk due to children's play: a case study.

During the 1920's and 1930's, a Niagara County, New York residential community, Belden Center, developed in tandem with two adjacent toxic waste disposal sites. During the period that they were in use, both sites were classified as public health hazards. Particularly between 1944 and 1979, as toxins were deposited, neighborhood children swam and played throughout the industrial waste sites. By reference to a large-scale map of the dumps, present residents described locations and types of play during their childhood. Assuming that a child would play away from home between 8 and 19 years of age, this allowed identification of cohorts that used the sites during different periods. An outcome map showing sites, dates, and types of play is the primary product of this investigation. More boys than girls played in the dumpsites, and we identified a subsample that did not use them for play. We conclude that children's play should be considered a major source of risk where communities lie next to toxic waste sites.

The China Productivity Project: results and conclusions.

Experiments were conducted to determine what factors cause variation in individual work output (economic productivity). Forty-five young male Chinese cycle haulers from Beijing were assessed for physiological work capacity, size and body composition, health, nutritional status, cold resistance, household social environment, and motivation. Experiments were conducted in the laboratory as well as under actual working conditions; ethnographic observations were made in the household and on the job during the Beijing winter of 1992. Overall work motivation correlated to actual monthly distance/load measures of productivity the most strongly (r = 0.518), followed by physiological capacity estimated by heart rate:speed ratio during field experiments (r = -0.473). Alcohol consumption (a negative factor), household health, and carbohydrate intake were all moderate predictors. Maximum oxygen uptake showed lower correlation (r = 0.261), and among anthropometric values only relatively long lower legs were predictive (r = 0.298). Since many of these variable categories were relatively independent of each other, multiple regression analysis showed that together they explained 61.6% of the work output variance. Simultaneous prediction by FASEM (LISREL) is also very strong.

An universal model of health and work output: theoretical structure and testing strategy.

The model proposed in this paper presents a broad range of factors to predict individual human work output. The predictors include aerobic capacity, body size, motivation, work pattern, social environment and social network, caloric intake, drug and alcohol use, stress resistance and thermoregulation. Health is a major intervening variable, and its relationship to work output is a special concern of this research. We suggest that this model may be used as a template to explain human productivity in most societies. Its universality can be subjected to rigorous testing in a range of settings from tropical upland swidden horticulturalists to urban workers in a northern industrialized country. Observations are offered on some of those testing sites and on methodological issues implicit in research of this breadth. A major pilot study of urban Chinese workers has already demonstrated the predictive power of the model in one setting.

Work performance of Chinese cycle haulers: controlled field experiments in normal work conditions.

Forty-five male Chinese cycle haulers performed a controlled field experiment under mild winter conditions. The objective was to gain insight into factors that affect work performance. Each man hauled the same 481-kg load around a Beijing street course of 14.18 km. The experiment was a measured sample of the same work they do routinely, on the same roads, using similar human powered hauling cycles (modified only enough to carry observers and instruments). The course was completed at a mean speed of 10.4 kph and mean time of 84.2 min. While there was considerable variation in individual pace and in pace change during work, the haulers performed at relatively high output in reference to their capacities. Mean heart rate was 156.8 +/- 16.1 bpm, 83.9% of maximum. The men had average body build and were average in size for the general Chinese population (X stature = 169.7 cm) although they showed relatively high aerobic capacity (determined in laboratory tests). Performance levels during experiments appear to match habitual work patterns, and self-pacing emerged as a major behavioral finding of this research. Speed, a primary index of job performance, showed significant correlation to heart rate, VO2max, variation in windchill, self-reported health and other variables, with a multiple regression coefficient of 0.811. Similar patterns were seen for heart rate relative to speed, except that physical size, education, and other behavioral variables were also predictors.

Stature in an early mid-19th century poorhouse population: Highland Park, Rochester, New York.

If the early 19th century United States was a developing country, then it may be expected that the lowest economic stratum would show some biological consequences of poverty. This report examines that question by estimating stature on 90 male and 64 female adult skeletons from an unmarked cemetery dating between 1826 and 1863. The Highland Park burial ground was adjacent to institutions which interned unfortunates of Rochester, Monroe County, in western New York. The best estimate of male stature (N = 84) is 172.6 cm. A review of other 18th and 19th century height data shows this value not to be relatively stunted, but rather exactly on the predicted mean of its time. If this was a poor population, stunting was not a consequence of poverty. Females (N = 59) showed a best height estimate of 160.0 cm. Less comparative data are available, but this too seems average for the time. A brief discussion of secular trends, changing income inequity and fluctuating stature from the 18th through 20th centuries puts this finding in context.

Stature variation in the British American Colonies: French and Indian War records, 1755-1763.

Personnel records kept by military units of American colonials during the French and Indian War (1755-1763) are analyzed for relationships between environmental factors and stature. A robust American economy and direct access to high-quality food were apparently critical to tallness of this white American male sample. American-born men were taller at all ages than those who had migrated from Europe. January temperatures, rural versus urban birth, and ethnicity also showed stature relationships within the American-born group; thermal effects were by far the strongest of the non-nutritional factors.

Skeletal stature compared to archival stature in mid-eighteenth century American: Ft. William Henry.

Fourteen soldiers buried at Ft. William Henry, New York, between 1755 and 1757 are compared for stature to a sample of 2,232 New York Provincial soldiers measured anthropometrically in 1760. The William Henry stature mean of 177.3 cm is significantly higher than that of the Provincials (169.7 cm), and their variation of stature is significantly lower-suggesting that the cemetery population was a select group. A historical explanation is offered for this unexpected finding.

Human nasal protrusion, latitude, and climate.

Relationships between morphological features of human skeletal nasal protrusion, latitude, and climate were investigated. Craniofacial dimensions and indices determined by Woo and Morant (1934) on a world sample of 55 skeletal populations were used as dependent variables. Sample sizes were as low as 39 in some calculations because either skeletal or geographic data were missing. Thirteen climatically related averaged variables, for each population's provenience, were the independent variables. Multivariate techniques of bivariate correlation, multiple regression, and partial correlation were applied. A strong, Statistically significant cline of increasing nose protrusion, with decreasing absolute humidity and with increasing latitude, was found. Cold climatic variables appeared to be of greater importance than warm measures. Similarly, absolute humidity was found to be a much better predictor of nose protrusion than was relative humidity.

Human facial temperatures in natural and laboratory cold.

Asian, European, and American Indian men were subjected to craniofacial cooling to determine relative ranking and temperature curves for various facial skin sites. Moving and still air 0 degrees C to -35 degrees C in both laboratory and subarctic outdoor settings were used. The objective was to examine resistance to facial frostbite. Facial temperatures stabilize well above freezing even under quite cold conditions and this conclusion is congruent with low incidences of facial frostbite. Racial differences in face temperatures were clearly shown at only the malar eminence, and there was some evidence that exercise can be used to enhance facial circulation. These results and those of other studies reviewed demonstrate that facial sites cooled by convection are usually ranked from forehead (warmest) through malar, cheek, and chin, to nose (coldest). When cooled by still air, the sites tend to retain that same ranking, but there is more variation in ranking.