Heavy metals and couple fecundity, the LIFE Study

The effect of heavy metals at environmentally relevant concentrations on couple fecundity has received limited study despite ubiquitous exposure. In 2005-2009, couples (n = 501) desiring pregnancy and discontinuing contraception were recruited and asked to complete interviews and to provide blood specimens for the quantification of cadmium (μg L⁻¹), lead (μg dL⁻¹) and mercury (μg L⁻¹) using inductively coupled plasma-mass spectrometry. Couples completed daily journals on lifestyle and intercourse along with menstruation and pregnancy testing for women. Couples were followed for 12 months or until pregnant. Fecundability odds ratios (FORs) and 95% confidence intervals (CIs) were estimated adjusting for age, body mass index, cotinine, and serum lipids in relation to female then male exposures. FORs <1 denote a longer time to pregnancy. In adjusted models, reduced FORs were observed for both female cadmium (0.78; 95% CI 0.63-0.97) and male lead (0.85; 95% CI 0.73-0.98) concentrations. When jointly modeling couples’ exposures, only male lead concentration significantly reduced the FOR (0.82; 95% CI 0.68, 0.97), though the FOR remained <1 for female cadmium (0.80; 95% CI 0.64, 1.00). This prospective couple based cohort with longitudinal capture of time to pregnancy is suggestive of cadmium and lead’s reproductive toxicity at environmentally relevant concentrations.     

Feasibility of water purification technology in rural areas of developing countries

Water scarcity is threatening social and economic growth in rural areas of developing countries. There are potential markets for water purification technologies in these regions. The main focus of this article is to evaluate the social, economic and political feasibilities of providing water purification technologies to rural areas of developing countries. The findings of this research can serve as the basis for private investors interested in entering this market. Four representative regions were selected for the study. Economic, demographic, and environmental variables of each region were collected and analyzed along with domestic markets and political information. Rural areas of the developing world are populated with poor people unable to fulfill the basic needs for clean water and sanitation. These people represent an important group of potential users. Due to economic, social, and political risks in these areas, it is difficult to build a strong case for any business or organization focusing on immediate returns on capital investment. A plausible business strategy would be to approach the water purification market as a corporate responsibility and social investing in the short term. This would allow an organization to be well positioned once the economic ability of individuals, governments, and donor agencies are better aligned.     

Geoelectrical methods for monitoring geological CO2 storage: First results from cross-hole and surface–downhole measurements from the CO2SINK test site at Ketzin (Germany)

The feasibility of monitoring CO₂ migration in a saline aquifer at a depth of about 650 m with cross-hole and surface–downhole electrical resistivity tomography (ERT) is investigated at the CO₂SINK test site close to Ketzin (Germany). The permanent vertical electrical resistivity array (VERA) consists of 45 electrodes (15 in the injection well Ktzi201 and 15 in each of the two observation wells Ktzi200 and Ktzi202), successfully placed on the electrically insulated casings, in the depth range of about 590–740 m with a spacing of about 10 m. The three Ketzin wells are arranged as perpendicular triangle with distances of 50 and 100 m.First synthetic modelling studies indicate an increase of the electrical resistivity of about 200% caused by CO₂ injection, corresponding to a bulk CO₂ saturation of 50%, which is in good agreement with laboratory studies. Finite difference inversion of field data delivers three-dimensional resistivity distributions between the wells which are consistent with the reservoir modelling studies.To increase the limited observation area provided by the cross-hole measurements, additional surface–downhole measurements were deployed. A main CO₂ migration in SE–NW direction is deduced from surface to downhole resistivity experiments.The first cross-hole time-lapse results show that the resolution and the coverage of the electrode array in the Ketzin setting are sufficient to resolve the expected resistivity changes on the characteristic length scale of the electrode array. Significant resistivity changes could be measured, however, detailed information on the CO₂ plume could not be resolved yet by VERA under the existing geological circumstances.     

What vehicle features are considered important when buying an automobile? An examination of driver preferences by age and gender

Introduction

Certain vehicle features can help drivers avoid collisions and/or protect occupants in the event of a crash, and therefore, might play an important role when deciding which vehicle to purchase. The objective of this study was to examine the importance attributed to key vehicle features (including safety) that drivers consider when buying a car and its association with age and gender.

Methods

A sample of 2,002 Canadian drivers aged 18 years and older completed a survey that asked them to rank the importance of eight vehicle features if they were to purchase a vehicle (storage, mileage, safety, price, comfort, performance, design, and reliability). ANOVA tests were performed to: (a) determine if there were differences in the level of importance between features and; (b) examine the effect of age and gender on the importance attributed to these features.

Results

Of the features examined, safety and reliability were the most highly rated in terms of importance, whereas design and performance had the lowest rating. Differences in safety and performance across age groups were dependent on gender. This effect was most evident in the youngest and oldest age groups.

Conclusions

Safety and reliability were considered the most important features. Age and gender play a significant role in explaining the importance of certain features.

Impact on Industry

Targeted efforts for translating safety-related information to the youngest and oldest consumers should be emphasized due to their high collision, injury, and fatality rates.     

Behavioral alterations due to diesel exhaust exposure

Several experiments examining the effects of diesel exhaust on the behavior of rats are reported. Animals were exposed either as adults or neonates. The spontaneous locomotor activity (SLA), measured in standard running wheel cages, of adult rats exposed for 8 h/day, 7 days/week was significantly less than that of controls. Experiments involving diesel exhaust exposure to neonatal rats indicated that adult rats, exposed to diesel exhaust during their neonatal lives, were significantly less active as measured by SLA. Adult rats, exposed to 20 h diesel per day as neonates, were placed in skinner boxes after the SLA experiment described above had been completed. The exhaust exposed animals showed significantly decreased acquisition of a food reinforced bar pressing task. All animals that learned this task extinguished at the same rate. The results of the neonatal diesel exhaust experiments support the hypothesis that diesel exhaust exposure during development of an organism can lead to behavioral differences in adulthood.     

Applications of Satellite Remote Sensing to Marine Pollution Studies

There are two approaches in the application of satellite sensors to marine pollution studies. Satellite sensors are used to observe and characterize ocean pollutants such as industrial wastes and oil. in addition, satellite observations provide information useful in illuminating processes such as eutrophi-cation or air-sea exchange of CO₂, that are important in determining the distribution and fate of pollutants.

Satellite technology is an important tool in monitoring and studying ocean pollution. Visible sensors have been used to observe and characterize sewage sludge and industrial wastes dumped at sea. Oil slicks have been observed with Landsat, AVHRR and SAR imagery. Besides directly detecting pollutants, satellite sensors are useful for analyzing ocean processes that are influential in the fate of pollutants. These processes include eutrophication of coastal waters and the distribution of suspended matter. the fate of excess CO₂ can be addressed using scatterometer-derived estimates of wind speeds to determine the CO₂ exchange coefficient at the sea surface on a global scale.     

WATER QUALITY CHARACTERISTICS OF STORM WATER FROM MAJOR LAND USES IN SOUTH FLORIDA1

ABSTRACT: Starting in 1998, a study was conducted to characterize storm water quality from predominant land use types in a coastal watershed along the south central coast of Florida, namely citrus, pasture, urban, natural wetland, row crop, dairy, and golf courses. Sixty‐three sampling sites were located at strategic points on drainage conveyances for each of seven specific land use areas. Runoff samples were collected following storm events that met defined rainfall criteria for a period of 30 months. Nitrogen (N), phosphorus (P), heavy metals, pesticides, and other water quality parameters were determined, and the results were analyzed to compare and characterize land uses as relative sources for these constituents in runoff. Results showed that runoff from most land use types had low dissolved oxygen concentration and that sediment and nutrient concentrations were closely related to land use, particularly to the amount of fertilizer applied in each land use. Among the eight heavy metals tested, copper was the most frequently detected and was mostly associated with runoff from citrus and golf course land uses. High levels of arsenic were also detected in golf course runoff. The most frequently detected pesticide was simazine from citrus. The information and methodologies presented may facilitate pollution source characterization and ecological restoration efforts.     

Gyrinid searching tactics: empirical observations and a tactical model

Summary Data on Gyrinus picipes were collected to examine the influence of prey distribution and capture on search path configuration. All paths were analyzed before and after prey capture. Parameters measured were turning angles, step lengths, and step direction. Three indices of search efficiency were calculated: linear displacement, thoroughness, and straightness. Prey distribution had little impact on search configuration. However, prey capture caused significant reductions in step length, linear displacement, and straightness. Thoroughnnes and turning angle increased significantly after prey capture.A simulation model was developed to analyze influences of search parameters on search efficiency. Search paths, simulated using empirically derived parameters, did not differ from actual search paths indicating that the model accurately describes gyrinid search paths and may be used in these analyses. Actual search paths were compared to a simulated Brownian (random) search. Search paths before prey capture were significantly different from random, but Brownian search can describe search paths after prey capture. Comparisons of simulations using various input parameters indicate that step length has the greatest effect on search paths. Turning angles and direction are important before prey capture but not after. Offprint requests to: D.L. Winkelman at his current address