Excrement from Heron colonies for environmental assessment of toxic elements

Excrement cast from Great Blue Heron nests was collected during the nesting period of 1978 from four colonies in Washington and Idaho. Cheesecloth strips placed on the ground beneath the nests served as excrement collecting devices. Chemical analysis for lead, mercury and cadmium were performed on dried samples. Lead was the most abundant trace metal found in heron debris. The Idaho colony at Lake Chatcolet had an average concentration of 46 ppm in the beneath-nest samples and 6 ppm in control samples. A heron colony near Tacoma, Washington had beneath-nest samples averaging 28 ppm and control samples averaging 20 ppm. Two colonies located in the interior region of Washington had substantially lower concentrations of lead. The difference observed between colonies was attributed to their associations with a polluted watershed (Chatcolet colony) an interstate highway (Tacoma colony) and an unpopulated largely agricultural area (inland Washington).     

Concentration and size distribution of ultrafine particles near a major highway

Motor vehicle emissions usually constitute the most significant source of ultrafine particles (diameter <0.1 microm) in an urban environment, yet little is known about the concentration and size distribution of ultrafine particles in the vicinity of major highways. In the present study, particle number concentration and size distribution in the size range from 6 to 220 nm were measured by a condensation particle counter (CPC) and a scanning mobility particle sizer (SMPS), respectively. Measurements were taken 30, 60, 90, 150, and 300 m downwind, and 300 m upwind, from Interstate 405 at the Los Angeles National Cemetery. At each sampling location, concentrations of CO, black carbon (BC), and particle mass were also measured by a Dasibi CO monitor, an aethalometer, and a DataRam, respectively. The range of average concentration of CO, BC, total particle number, and mass concentration at 30 m was 1.7-2.2 ppm, 3.4-10.0 microg/m3, 1.3-2.0 x 10(5)/cm3, and 30.2-64.6 microg/m3, respectively. For the conditions of these measurements, relative concentrations of CO, BC, and particle number tracked each other well as distance from the freeway increased. Particle number concentration (6-220 nm) decreased exponentially with downwind distance from the freeway. Data showed that both atmospheric dispersion and coagulation contributed to the rapid decrease in particle number concentration and change in particle size distribution with increasing distance from the freeway. Average traffic flow during the sampling periods was 13,900 vehicles/hr. Ninety-three percent of vehicles were gasoline-powered cars or light trucks. The measured number concentration tracked traffic flow well. Thirty meters downwind from the freeway, three distinct ultrafine modes were observed with geometric mean diameters of 13, 27, and 65 nm. The smallest mode, with a peak concentration of 1.6 x 10(5)/cm3, disappeared at distances greater than 90 m from the freeway. Ultrafine particle number concentration measured 300 m downwind from the freeway was indistinguishable from upwind background concentration. These data may be used to estimate exposure to ultrafine particles in the vicinity of major highways.     

Engaging with the natural environment: The role of affective connection and identity

Research has shown pro-environmental behaviour to be positively associated with the strength of emotional connection towards the natural environment. The present study (N=199) investigated the predictive utility of an extended model of the theory of planned behaviour (TPB) [ Ajzen, I. (1991). The theory of planned behaviour. Organizational Behaviour and Human Decision Processes, 50, 179–211] for people's intentions to engage with the natural environment. It was hypothesised that both affective connection and identification with the natural environment would contribute significantly to the prediction of people's intentions. A secondary hypothesis was that participants who had grown up in rural areas would report more positive orientations towards engaging with the natural environment than would urban participants. The research found that affective connection was a significant independent predictor of intentions to engage with the natural environment. Environmental identity was only a significant predictor in the absence of affective connection in the regression model. As predicted, rural and urban participants differed significantly along the measured variables.     

Elk River Completes Second Year With Zero Bag Failures Reported

Abstract

This paper presents results from a study conducted in two urban areas of southern California, Downey and Riverside, to examine the effect of different sources and formation mechanisms on the size distribution and temporal trends of ultrafine particles. Near-continuous data were collected for 5 months at each location. Our data clearly identified Downey as a source site, primarily affected by vehicular emissions from nearby freeways, and Riverside as a receptor site, where photochemical secondary reactions form a substantial fraction of particles, along with local vehicular emissions. In Downey, the diurnal trends of total particle number concentration and elemental carbon (EC) appear to be almost identical throughout the day and irrespective of season, thereby corroborating the role of primary emissions in the formation of these particles. This agreement between EC and particle number was not observed in Riverside during the warmer months of the year, while very similar trends to Downey were observed during the winter months in that area. Similarly, the size distribution of ultrafine particles in Downey was generally unimodal with a mode diameter of 30–40 nm and without significant monthly variations. The number-based particle size distributions obtained in Riverside were bimodal, with a significant increase in accumulation mode as the season progressed from winter to summer. During the warmer months, there was also an increase in sub-100-nm particles in the afternoon hours, between 2:00 p.m. and 4:00 p.m., that also increased with the temperature. The differences observed in the ultrafine particle distribution and temporal trends clearly demonstrated that mechanisms other than direct emissions play an important role in the formation of ultrafine particles in receptor sites of the Los Angeles Basin.     

Measurements of ultrafine particles and other vehicular pollutants inside a mobile exposure system on Los Angeles freeways

A mobile exposure and air pollution measurement system was developed and used for on-freeway ultrafine particle health effects studies. A nine-passenger van was modified with a high-efficiency particulate air (HEPA) filtration system that can deliver filtered or unfiltered air to an exposure chamber inside the van. State-of-the-art instruments were used to measure concentration and size distribution of fine and ultrafine particles and the concentration of carbon monoxide (CO), black carbon (BC), particle-bound polycyclic aromatic hydrocarbons (PAHs), fine particulate matter (PM2.5) mass, and oxides of nitrogen (NOx) inside the exposure chamber. This paper presents the construction and technical details of the van and air pollutant concentrations collected in 32 2-hr runs on two major Los Angeles freeways, Interstate 405 (1-405; mostly gasoline traffic) and Interstate 710 (1-710; large proportion of heavy-duty diesel traffic). More than 97% of particles were removed when the flow through the filter box was switched from bypass mode to filter mode while the vehicle was driving on both freeways. The filtration system thus provides a great particulate matter exposure contrast while keeping gas-phase pollutant concentrations the same. Under bypass mode, average total particle number concentration observed inside the exposure chamber was around 8.4 x 10(4) and 1.3 x 10(5) particles cm(-3) on the I-405 and the I-710 freeways, respectively. Bimodal size distributions were consistent and similar for both freeways with the first mode around 16-20 nm and the second mode around 50-55 nm. BC and particle-bound PAH concentrations were more than two times greater on the I-710 than on the I-405 freeway. Very weak correlations were observed between total particle number concentrations and other vehicular pollutants on the freeways.     

Biochemical and cellular effects of electrophiles present in ambient air samples

Ambient vapor-phase samples collected in Riverside, California had shown that both redox and electrophilic activity were present, with the vapor phase containing higher levels of electrophiles than the particle phase. In this study, the biochemical effects of the vapor-phase electrophiles were examined using the purified thiol proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), protein tyrosine phosphatase 1B (PTP1B) and KELCH-1 like ECH-associated protein 1 (Keap1). The results demonstrated that the thiol proteins were inactivated by the vapor-phase samples through covalent modifications. Next, two cellular responses, epidermal growth factor receptor (EGFR)/mitogen-activated protein (MAP) kinase and NF-E2-related factor 2 (Nrf2), to the ambient vapor-phase samples were assessed in A549 and RAW 264.7 cell lines, respectively. The vapor-phase samples, at non-oxidative concentrations, increased phosphorylation of EGFR, which is negatively regulated by PTP1B, and its downstream MAP kinase, extracellular signal-regulated kinase (ERK)1/2. Activation of Nrf2, which requires Keap1 alkylation, and expression of its downstream proteins were also observed. The electrophilic compounds present in ambient vapor-phase were shown to modify cellular proteins through covalent modification and to activate diverse cellular responses that can lead to inflammatory and adaptive responses.     

Small island developing states and sustainable development of ocean resources

Because of their economic and environmental vulnerability, small island developing states (SIDS) have peculiar developmental problems that severely affect their ability to implement the measures necessary for attaining sustainable development as recommended in UNCED's Agenda 21. Although this has been recognised by the Commission on Sustainable Development (CSD), and although there has been international acceptance of a SIDS Programme of Action (POA), SIDS have not been the focus of adequate attention by international and donor agencies. As a result, progress toward implementing the POA has been disappointing. This study examines the question of how sustainable management and development of ocean resources can contribute significantly to the achievement of the objectives of the SIDS POA.