Application of a permethrin immunosorbent assay method to residential soil and dust samples

A low-cost, high throughput bioanalytical screening method was developed for monitoring cis/trans-permethrin in dust and soil samples. The method consisted of a simple sample preparation procedure [sonication with dichloromethane followed by a solvent exchange into methanol:water (1:1)] with bioanalytical detection using a magnetic particle enzyme-linked immunosorbent assay (ELISA). Quantitative recoveries (83–126 %) of cis/trans-permethrin were obtained for spiked soil and dust samples. The percent difference of duplicate ELISA analyses was within ± 20 % for standards and ± 35 % for samples. Similar sample preparation procedures were used for the conventional gas chromatography/mass spectrometry (GC/MS) analysis except that additional cleanup steps were required. Recoveries of cis/trans-permethrin ranged from 81 to 108 % for spiked soil and dust samples by GC/MS. The ELISA-derived permethrin concentrations were highly correlated with the GC/MS-derived sum of cis/trans-permethrin concentrations with a correlation coefficient (r) of 0.986. The ELISA method provided a rapid qualitative screen for cis/trans-permethrin in soil and dust while providing a higher sample throughput with a lower cost as compared to the GC/MS method. The ELISA can be applied as a complementary, low-cost screening tool to prioritize and rank samples prior to instrumental analysis for exposure studies.     

Urbanisation and human health in China: spatial features and a systemic perspective

Background, aims and scope

Current studies have paid little attention to the dynamism in urban spatial expansion and its possible environmental and health effects or to the health effects of rapid urban environmental change at different points along the urbanisation gradient. This study adopts a public health ecology approach to systematically understand the relationship between urbanisation, urban environmental change and human health in China.

Method

Remote sensing image analysis, based on night light data at five different time periods in recent decades, was used to determine changes to the overall urban area. Through a review of the evidence on the relationships between environmental health, urbanisation and health, we advance a pathway framework for explaining urban human health ecology. The Spearman rank correlation coefficient was used to measure the correlation between disease prevalence and urbanisation level, adding a further dimension to a systemic understanding of urban health.

Results and conclusions

Urban areas have been increasing spatially, but unevenly, in recent decades, with medium and small cities also expanding rapidly in the past decade. Urbanisation and urban expansion result in changes to land use/coverage change, the urban environment and the residents?? lifestyle, which result in human health problems. Regions with the highest urbanisation level were more inclined to have a high prevalence of chronic disease in recent decades. An ecological public health approach provides insights into the multiple types of data which need to be routinely collected if human disease is not to become a barrier to social and economic development.     

An enzyme-linked immunosorbent assay for the determination of dioxins in contaminated sediment and soil samples

A 96-microwell enzyme-linked immunosorbent assay (ELISA) method was evaluated to determine PCDDs/PCDFs in sediment and soil samples from an EPA Superfund site. Samples were prepared and analyzed by both the ELISA and a gas chromatography/high resolution mass spectrometry (GC/HRMS) method. Comparable method precision, accuracy, and detection level (8 ng kg(-1)) were achieved by the ELISA method with respect to GC/HRMS. However, the extraction and cleanup method developed for the ELISA requires refinement for the soil type that yielded a waxy residue after sample processing. Four types of statistical analyses (Pearson correlation coefficient, paired t-test, nonparametric tests, and McNemar's test of association) were performed to determine whether the two methods produced statistically different results. The log-transformed ELISA-derived 2,3,7,8-tetrachlorodibenzo-p-dioxin values and log-transformed GC/HRMS-derived TEQ values were significantly correlated (r=0.79) at the 0.05 level. The median difference in values between ELISA and GC/HRMS was not significant at the 0.05 level. Low false negative and false positive rates (<10%) were observed for the ELISA when compared to the GC/HRMS at 1,000 ng TEQ kg(-1). The findings suggest that immunochemical technology could be a complementary monitoring tool for determining concentrations at the 1,000 ng TEQ kg(-1) action level for contaminated sediment and soil. The ELISA could also be used in an analytical triage approach to screen and rank samples prior to instrumental analysis.     

Environmental evaluation for workplace violence in healthcare and social services

PROBLEM: Federal policy recommends environmental strategies as part of a comprehensive workplace violence program in healthcare and social services. The purpose of this project was to contribute specific, evidence-based guidance to the healthcare and social services employer communities regarding the use of environmental design to prevent violence. METHOD: A retrospective record review was conducted of environmental evaluations that were performed by an architect in two Participatory Action Research (PAR) projects for workplace violence prevention in 2000 and, in the second project in 2005. Ten facility environmental evaluation reports along with staff focus group reports from these facilities were analyzed to categorize environmental risk factors for Type II workplace violence. RESULTS: Findings were grouped according to their impact on access control, the ability to observe patients (natural surveillance), patient and worker safety (territoriality), and activity support. DISCUSSION: The environmental assessment findings reveal design and security issues that, if corrected, would improve safety and security of staff, patients, and visitors and reduce fear and unpredictability. IMPACT ON INDUSTRY: Healthcare and social assistance employers can improve the effectiveness of violence prevention efforts by including an environmental assessment with complementary hazard controls.     

Repellent scent-marking of flowers by a guild of foraging bumblebees (Bombus spp.)

We have found that foraging bumblebees (Bombus hortorum, B. pascuorum, B. pratorum and B.␣terrestris) not only avoid flowers of Symphytum officinale that have recently been visited by conspecifics but also those that have been recently visited by heterospecifics. We propose that the decision whether to reject or accept a flower is influenced by a chemical odour that is left on the corolla by a forager, which temporarily repels subsequent foragers. Honeybees and carpenter bees have previously been shown to use similar repellent forage-marking scents. We found that flowers were repellent to other bumblebee foragers for approximately 20 min and also that after this time nectar levels in S. officinale flowers had largely replenished. Thus bumblebees could forage more efficiently by avoiding flowers with low rewards. Flowers to which extracts of tarsal components were applied were more often rejected by wild B. terrestris workers than flowers that had head extracts applied, which in turn were more often rejected than flowers that had body extracts applied. Extracts from four Bombus species were equally repellent to foragers. The sites of production of the repellent scent and its evolutionary origins are discussed. Received: 24 November 1997 / Accepted after revision: 8 March 1998     

Proactive environmental management is the key to full compliance

There are two key elements to achieving full and complete regulatory compliance: cost-efficient management of current regulatory requirements under existing environmental law and the capability to anticipate and analyze the impact of future regulations on the facility. The author provides step-by-step advice on how to develop a program to accomplish a corporate goal of zero violations.     

Storage stability of injection-molded starch-zein plastics under dry and humid conditions

Corn starch and zein mixtures (4 : 1 dry weight) were extruded and injection-molded in the presence of plasticizers (glycerol and water). Tensile strength and percentage elongation of the molded plastics were measured before and after 1 week of storage under a dry or humid condition (11 or 93% RH). With 10–12% glycerol and 6–8% water, injection-molded plastics had relatively good tensile properties (20- to 25-MPa tensile strength and 3.5–4.7% elongation). But while exposed to dry conditions (11% RH), the molded plastics lost weight (0.5–1.5% in 7 days) and became very brittle, with significant decreases in tensile strength and elongation. Partial replacement (5–10%) of starch with a maltodextrin (average DE 5) reduced the glass transition and melting temperatures of the starch-zein mixture as well as the dry storage stability. Using potato starch instead of corn starch significantly improved the dry storage stability of the injection-molded starch-zein plastics (18- vs 11-MPa tensile strength). Anionic corn starches with a maleate or succinate group (DS<0.01) produced injection-molded plastics with improved tensile properties and storage stability. Plastics prepared from the starch maleate and zein mixture retained the strength during 1 week of dry storage without a significant change (26-MPa tensile strength and 3.7% elongation after 1 week of storage).Paper presented at the Bio/Environmentally Degradable Polymer Society—Second National Meeting, August 19–21, 1993, Chicago, Illinois.Journal paper No. J-15561 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project No. 2863.     

Biodegradable plastic made from soybean products. II. Effects of cross-linking and cellulose incorporation on mechanical properties and water absorption

Soy isolate was treated with formaldehyde and glyoxal at 1.0, 2.5, and 5.0% (w/w isolate) and with adipic and acetic anhydrides. The materials were then compression-molded into plastic tensile bars and tested for tensile and yield strength, percentage elongation, Young's modulus, and water absorption. Treatment with 5% formaldehyde increased the tensile strength significantly, to 4.9 kg/mm², compared with the untreated sample (3.7 kg/mm²). The yield strength increased slightly, to 0.68 kg/mm². Elongation was significantly less after treatment with formaldehyde. Young's modulus increased after treatment and leveled off at 174 kg/mm². Water absorption decreased as the formaldehyde concentration increased. Treatment with either glyoxal or adipic/acetic anhydride had a detrimental effect on the mechanical properties of the plastic specimens. Water absorption was decreased by glyoxal treatment but was not affected by adipic/acetic anhydride treatment. Long-fiber (lf), short-fiber (sf), and microcrystalline (mc) cellulose were incorporated into soy isolate at various levels. Cellulose addition decreased the percentage elongation and increased the rigidity of the plastic. All three cellulose additions increased Young's modulus. The tensile strength increased with the addition of sf-cellulose to soy isolate; lf-cellulose decreased the tensile strength, whereas the incorporation of mc-cellulose did not have a significant effect. The yield strength increased slightly with the addition of sf-cellulose and was less affected by the addition of lf- or mc-cellulose. All three types of cellulose slightly decreased water absorption at ca. 15% content.Journal Paper No. J-15563 of the Iowa Agriculture and Home Economics Experiment Station, Ames; Project No. 2863.     

The Colorado,USA, Joint Review Process: an initial evaluation of its success as a permit reform by key participants

Colorado, USA, developed the Joint Review Process (CJRP) in 1978 to coordinate the application and review of permits required for major development projects. Since then, the state has used the process on over 20 projects. This study examined whether the CJRP has achieved its primary goals—enhanced coordination of agencies, enhanced public participation, and strengthened communication between agencies and project sponsors— and several related secondary goals. The success of the process was measured through a survey of 54 key people who had been directly involved with the process. Those surveyed included federal and state agency staff, local agency managers, corporate officers, private consultants, and environmental leaders. All groups, with one exception, agreed that the process achieved its primary goals and that it should be retained. Environmental leaders were neutral about whether the process enhanced public participation and about retaining the process. The report concludes with a review of recommended improvements to and applications of the CJRP.