GROUNDWATER QUALITY IN THE CORTARO AREA NORTHWEST OF TUCSON,ARIZONA1

ABSTRACT The Cortaro Area is currently the depository for much of the liquid waste from the City of Tucson. In the past, more than one-half of the sewage effluent was used for crop irrigation. However, since 1970 virtually all of the sewage effluent has been percolated in the normally dry Santa Cruz River channel. Nitrate and chloride contents were monitored monthly in water samples from about 20 large-capacity irrigation wells. Contents and seasonal trends for these constituents were closely related to the disposal of sewage effluent. Water quality problems other than nitrate include total dissolved solids, boron, coliform, and lead. High lead contents in the area appear to be a natural phenomenon and the coliform contents are likely related to poor well construction. The other quality problems are primarily due to sewage effluent.     

Ecological planning: A review

Beginning with the passage of the National Environmental Policy Act in 1969, the federal government of the United States has enacted numerous pieces of legislation intended to protect or conserve the environment. Other national governments have also enacted environmental legislation during the past two decades. State and local governments have also adopted policies concerned with environmental planning and management. Multiple laws and overlapping governmental agency responsibilities have confused development and resource management efforts. A comprehensive methodology that integrates the legal mandates and the agency missions into a common and unified framework is needed. Ecological planning offers such a method. Application of the method allows planners and resource managers to better understand the nature and character of the land and/or resource and therefore make better decisions about its appropriate use or management. The steps taken in an ecological planning process—1) goal setting, 2) inventory and analysis of data, 3) suitability analysis, 4) developing alternatives, 5) implementation, 6) administration, and 7) evaluation—are outlined and explained. Hand-drawn overlays and computer programs as techniques for handling ecological planning information are compared. Observations and suggestions for further research are offered.     

Street floods in Metro Manila and possible solutions

Urban floods from thunderstorms cause severe problems in Metro Manila due to road traffic. Using Light Detection and Ranging (LiDAR)-derived topography, flood simulations and anecdotal reports, the root of surface flood problems in Metro Manila is identified. Majority of flood-prone areas are along the intersection of creeks and streets located in topographic lows. When creeks overflow or when rapidly accumulated street flood does not drain fast enough to the nearest stream channel, the intersecting road also gets flooded. Possible solutions include the elevation of roads or construction of well-designed drainage structures leading to the creeks. Proposed solutions to the flood problem of Metro Manila may avoid paralyzing traffic problems due to short-lived rain events, which according to Japan International Cooperation Agency (JICA) cost the Philippine economy 2.4 billion pesos/day.     

Case study approach to modeling historical disinfection by-product exposure in Iowa drinking waters

In the 1980 s, a case–control epidemiologic study was conducted in Iowa(USA) to analyze the association between exposure to disinfection by-products(DBPs) and bladder cancer risk. Trihalomethanes(THMs), the most commonly measured and dominant class of DBPs in drinking water, served as a primary metric and surrogate for the full DBP mixture.Average THM exposure was calculated, based on rough estimates of past levels in Iowa. To reduce misclassification, a follow-up study was undertaken to improve estimates of past THM levels and to re-evaluate their association with cancer risk. In addition, the risk associated with haloacetic acids, another class of DBPs, was examined. In the original analysis, surface water treatment plants were assigned one of two possible THM levels depending on the point of chlorination. The re-assessment considered each utility treating surface or groundwater on a case-by-case basis. Multiple treatment/disinfection scenarios and water quality parameters were considered with actual DBP measurements to develop estimates of past levels. The highest annual average THM level in the re-analysis was156 μg/L compared to 74 μg/L for the original analysis. This allowed the analysis of subjects exposed at higher levels( 96 μg/L). The re-analysis established a new approach, based on case studies and an understanding of the water quality and operational parameters that impact DBP formation, for determining historical exposure.     

颗粒载体生物滴滤床处理低浓度污水对比试验研究

选用生物陶粒和Hat Creek煤两种颗粒载体,应用于滴滤床颗粒填料生物反应器模型中,进行去除有机污染物的性能对比试验研究。研究表明,生物陶粒可作为滴滤床填料去除低浓度污水中的有机污染物,但在贫营养条件时,处理效果不如Hat Creek煤;而在进水浓度或水量增加,营养不成为限定因素的运行条件下,其极限负荷与处理效果明显要优于Hat Creek煤。     

Alternative mating behaviors of the queen polymorphic ant <Emphasis Type="Italic">Temnothorax longispinosus</Emphasis>

Mating behaviors of ants fall into two categories: female calling, in which a female alate releases pheromones that attract males, and male swarming, in which large male aggregations attract females. Female calling is common in species with queens that return to their natal nest to found colonies dependently after mating, while male swarming is common in species with queens that disperse to found independently. In some species that display both founding strategies, a queen-size polymorphism has evolved in which dependent-founding queens are smaller than independent-founding queens. Dependent founding is likely difficult if gynes (virgin queens) are mating in distant swarms. Therefore, a queen may adopt one or the other mating strategy based on its size and founding behavior. We investigated mating behaviors in the queen-polymorphic ant, Temnothorax longispinosus. Observations in laboratory mating arenas indicated that small gynes exhibited significantly lower flight activity than large gynes. Both forms mated in male swarms, and neither form exhibited female calling. The reduced flight activity of the small morph may facilitate returning to the natal nest after mating, provided the mating swarm is located nearby. Therefore, alternative colony-founding behaviors may be possible without the evolution of female-calling behavior; however, the reduced flight activity of small morphs may require that mating swarms are not distant from the natal nest.     

Trust in Sources of Soil and Water Quality Information: Implications for Environmental Outreach and Education

Public trust in organizations focused on improving environmental quality is important for increasing awareness and changing behaviors that have water quality implications. Few studies have addressed trust in soil and water quality information sources, particularly for both agricultural and nonagricultural respondents of the same watersheds. Surveys in 19 watersheds across five states in the Midwest assessed trust in, and familiarity with, soil and water quality information sources. Overall, respondents most trusted University Extension, Soil and Water Conservation Districts, and the Natural Resource Conservation Service, while lawn care companies, environmental groups, and land trusts were less trusted. Significant differences in trusted sources were found between watersheds, and between agricultural and nonagricultural respondents across and within watersheds. Among agricultural respondents, a clear relationship exists between familiarity and trust; as familiarity with an organization increases, so too does level of trust. This relationship is less clear‐cut for nonagricultural respondents in this region. We highlight implications of these findings for soil and water quality outreach efforts.     

SOCIOECONOMIC IMPACTS OF CLIMATE CHANGE ON U.S. WATER SUPPLIES1

ABSTRACT: A greenhouse warming would have major effects on water supplies and demands. A framework for examining the socioeconomic impacts associated with changes in the long-term availability of water is developed and applied to the hydrologic implications of the Canadian and British Hadley2 general circulation models (GCMs) for the 18 water resource regions in the conterminous United States. The climate projections of these two GCMs have very different implications for future water supplies and costs. The Canadian model suggests most of the nation would be much drier in the year 2030. Under the least-cost management scenario the drier climate could add nearly $105 billion to the estimated costs of balancing supplies and demands relative to the costs without climate change. Measures to protect instream flows and irrigation could result in significantly higher costs. In contrast, projections based on the Hadley model suggest water supplies would increase throughout much of the nation, reducing the costs of balancing water supplies with demands relative to the no-climate-change case.     

Exploratory analysis of the association between pyrethroid exposure and rheumatoid arthritis among US adults: 2007–2014 data analysis from the National Health and Nutrition Examination Survey (NHANES)

Environmental Science and Pollution Research - Previous studies indicate that pesticide use may play an important role in the occurrence and development of rheumatoid arthritis (RA); however,...