Evaluation and optimization of an urban PM2.5 monitoring network

The objective of this study was to evaluate the PM(2.5) monitoring network established in the Greater Cincinnati and Northern Kentucky metropolitan area for measuring the 24 h integrated PM(2.5) concentration, as well as-at selected sites-hourly PM(2.5) concentration and 24 h integrated PM(2.5) speciation. The data collected during three years at 13 measurement sites were analyzed for spatial and temporal variations. It was found that both daily and hourly concentrations of PM(2.5) have low spatial variation due to a regional influence of secondary ammonium sulfate. In contrast, the trace element concentrations had high spatial variation. Seasonal variation accounted for most of the total temporal variation (60%), while yearly, monthly, weekly and daily variations were lower. The variance components and cluster analyses were applied to optimize the number of sites for measuring the 24 h PM(2.5) concentration. It was found that the 13-site network may be optimized by reducing the number of sites to 8, which would result in a relative precision reduction of 9% and a relative cost reduction of 36%. At the same time, the data suggest that the spatial resolution of speciation monitors and real-time PM(2.5) mass monitors should be increased to better represent spatial and temporal variations of the markers of local air pollution sources.     

Behaviour and mobility of preemergent herbicides in turfgrass: A field study

Abstract

The quality of many golf courses and other turfgrass areas often requires high levels of cultural management. The fact that this level of maintenance usually includes the use of preemergent herbicides has caused concern about their potential for ground water contamination. Much of this concern is based on extrapolation from agricultural situations rather than data developed from studies conducted in field turfgrass situations. To address this data gap, a two‐year field project evaluating the behaviour and mobility of the commonly used preemergent herbicides, benfluralin, trifluralin, bensulide, oxadiazon. pendimethalin, and DCPA with its two metabolites was conducted at OARDC/The Ohio State University, Wooster, Ohio, in 1988–89. Plots were located on a site with thatch (WT) and one with no thatch (NT)to further clarify the impact of thatch on herbicide behavior. Treatments were applied in April and samples of thatch and four zones of soil (0–2.5, 2.5–5, 7.5–10 and 22.5–25cm) were collected throughout the year and analyzed for residue dissipation. Residues of pendimethalin, benfluralin, and trifluralin in the 22.5–25 cm zone were below the limit of determination. No detectable oxadiazon residues were found in this zone at the WT site in 1988 but on two occasions, residues of 0.01 and 0.02 kg/ha were found in 1989. At the NT site, residues in this zone on one occasion were 0.02 kg/ha in 1988 and none in 1989. Residues of bensulide in the same zone ranged not detectable (ND)‐0.02 kg/ha in both locations. The DCPA residues in the 22.5–25 cm zone ranged ND‐0.10 kg/ha (WT), ND‐0.27 kg/ha (NT) in 1988. and ND‐0.02 kg/ha (WT), ND‐0.04 kg/ha (NT) in 1989. The residues of SDS 1449, the less stable of two dacthal metabolites, were very low but higher in 1988 than in 1989 in both locations. The SDS 954 residues in 22.5–25 cm zone ranged ND‐0.1 kg/ha (WT), and ND‐0.16 kg/ha (NT) in 1988, and ND‐0.26 kg/ha (WT), and ND‐0.27 kg/ha (NT) in 1989.

Some amount of all herbicides applied carried over into the spring of the year following application but oxadiazon and bensulide were the most persistent.     

Successful Use of Advertisement Pictures to Assist Recall in a Food-Borne Hepatitis A Outbreak in The Netherlands, 2017

This study describes an outbreak investigation of 14 hepatitis A cases in the Netherlands. The hepatitis A virus (HAV) genotype IB sequences in cases were highly similar (459/460 nt). The origin of strains could be narrowed to Bulgaria based on information from EPIS-FWD. As an association with consumption of soft fruit was suspected, a case–control study was initiated using a questionnaire and a list of pictures of soft fruit available at the supermarket chain involved. Twelve out of 13 cases consumed a specific frozen raspberry/blueberry product shown on the list (OR 46.0, 95% CI 5.0–27). In multivariable regression analysis this product was the only risk factor (aOR 26.6, 95% CI 2.0–263). Laboratory analyses could not demonstrate HAV-RNA in batches that had been on the market in the incubation period of patients. Trace back of frozen fruit showed that raspberries had been traded by a producer in Bulgaria. After withdrawal of the product from the supermarket no new cases were reported. Use of advertisement pictures of consumed food was helpful in this investigation. Suspicion of the source was strengthened by data from molecular typing and food trace back activities, underlining the importance of good (inter)national cooperation between public health and food safety organisations.     

Zoogeography of fish parasites of the pearlside (Maurolicus muelleri), with genetic evidence of Anisakis simplex (s.s.) from the Mid-Atlantic Ridge

A total of 200 Maurolicus muelleri from the Mid-Atlantic Ridge (MAR) and the Norwegian Deep (ND) were studied for parasitic helminths. Two different metazoans were isolated from the MAR and five species from the ND. The predominant parasite species in both areas were tetraphyllidean cestode larvae (Scolex pleuronectis) and the anisakid nematode Anisakis simplex sensu stricto (s.s.), the latter being identified using genetic analysis of the internal transcribed spacer (ITS-1, ITS-2) and 5.8S regions of the rDNA. The parasite fauna of M. muelleri from the MAR was less species rich in comparison to ND, due to the deep-sea and oceanic environment. The digeneans Brachyphallus crenatus and Lecithaster confusus as well as the raphidascarid fish nematode Hysterothylacium aduncum were only collected from the ND. This can be explained either by the deep origin of the sampled fish specimens or the lack of suitable intermediate or final hosts in the region. Based on the frequent occurrence of A. simplex (s.s.) around the MAR and the ND, a pelagic life cycle is suggested at both localities, involving baleen and toothed whales as final and pelagic and mesopelagic fish and invertebrates as intermediate or paratenic hosts.     

Cytotoxic activity of spark‐decomposed sulfur hexafluoride and analysis of cytotoxic contributions of individual spark decomposition products†

Sulfur hexafluoride decomposed by electrical sparks has been found to by cytotoxic to hamster cells when tested in an in vitro cell survival assay, while SF₆ shows no cytotoxic activity. Chemical analysis of spark‐decomposed SF₆ has identified and quantified the following compounds: SOF₂, SO₂F₂, SF₄, SOF₄, SiF₄, SO₂ and HF. Each of these gases, at concentration ranges expected in spark‐decomposed SF₆, were tested for cytotoxic activity toward hamster cells. Of the gases showing cytotoxic activity, SO₂F₂ and SOF₄ were similar in activity, as were SOF₂ and SF₄, while the behavior of SiF₄ was different from the rest. None of these individual gases, at concentrations expected in spark‐decomposed SF₆, has sufficient cytotoxic activity to account for the cytotoxic effect of spark‐decomposed SF₆ observed in our assay system. A four‐component mixture of some of the gases enumerated above (at concentrations overestimating their abundance in spark‐decomposed SF₆) was much less cytotoxic than the spark‐decomposed SF₆ gas. A mathematical simulation of the cytotoxic activity of a mixture of gases at concentrations found in spark‐decomposed SF₆ was made, assuming independent cytotoxic effects from each component. The simulated cytotoxic effect thus computed was less than that seen in spark‐decomposed SF₆. Since individual components or mixtures of the major decomposition products do not account for the observed biological activity of spark‐decomposed SF₆, this suggests there may be one or more components, present in the spark‐decomposed gas at very low concentrations, which may have a very strong cytotoxic activity.     

Evaluating animal personalities: do observer assessments and experimental tests measure the same thing?

The animal personality literature uses three approaches to assess personality. However, two of these methods, personality ratings and experimentation, have been little compared in captivity and never compared in the wild. We assessed the boldness of wild chacma baboons Papio ursinus using both ratings and experimental methods. Boldness was experimentally assessed when individuals were presented with a novel food item during natural foraging. The boldness of the same individuals was rated on a five-point scale by experienced observers. The ratings and experimental assessments of boldness were found to correlate positively and in a linear fashion. When considered categorically the two approaches showed variable agreement depending on the number of categories assigned and the cut-off criteria adopted. We suggest that the variation between approaches arises because each method captures different aspects of personality; ratings consider personality in absolute terms (using predefined criteria) and multiple contexts, while experimental assessments consider personality in relative terms (using experimental scores relative to the population average) and in limited contexts. We encourage animal personality researchers to consider adopting both methodologies in future studies. We also propose that future studies restrict their analyses to continuous data, since the greatest comparability between methods was found with these data. However, if individuals must be categorised, we suggest that researchers either (a) analyse only those individuals categorised as bold or shy by both ratings and experimental approaches or, if these methods cannot be employed simultaneously, (b) do not use approach-specific criteria but choose a cut-off that can be compared by both approaches.     

Plant-soil feedback: testing the generality with the same grasses in serpentine and prairie soils

Plants can alter soil properties in ways that feed back to affect plant performance. The extent that plant-soil feedback affects co-occurring plant species differentially will determine its impact on plant community structure. Whether feedback operates consistently across similar plant communities is little studied. Here, the same grasses from two eastern U.S. serpentine grasslands and two midwestern tallgrass prairie remnants were examined for plant-soil feedback in parallel greenhouse experiments. Native soils were homogenized and cultured (trained) for a year with each of the four grasses. Feedback was evaluated by examining biomass variation in a second generation of (tester) plants grown in the trained soils. Biomass was lower in soils trained by conspecifics compared to soils trained by heterospecifics in seven of 15 possible cases; biomass was greater in conspecific soils in one other. Sorghastrum nutans exhibited lower biomass in conspecific soils for all four grasslands, so feedback may be characteristic of this species. Three cases from the Hayden prairie site were explained by trainer species having similar effects across all tester species so the relative performance of the different species was little affected; plants were generally larger in soils trained by Andropogon gerardii and smaller in soils trained by S. nutans. Differences among sites in the incidence of feedback were independent of serpentine or prairie soils. To explore the causes of the feedback, several soil factors were measured as a function of trainer species: nutrients and pH, arbuscular mycorrhizal (AM) spore communities, root colonization by AM fungi and putative pathogens, and functional diversity in bacterial communities as indicated by carbon substrate utilization. Only variation in nutrients was consistent with any patterns of feedback, and this could explain the greater biomass in soils trained by A. gerardii at Hayden. Feedback at Nottingham (one of the serpentine sites) differed, most notably for A. gerardii, from that of similar past studies that used different experimental protocols. To understand the consequences of feedback for plant community structure, it is important to consider how multiple species respond to the same plant-induced soil variation as well as differences in the feedback detected between greenhouse and field settings.     

ACCUMULATION OF AS,NI, CU,AND PB IN RETENTION AND RECHARGE BASINS SOILS FROM URBAN RUNOFF1

ABSTRACT: The accumulation of arsenic, nickel, copper, and lead in the soil profile was determined beneath five urban storm-water retention/recharge basins used by the Fresno Metropolitan Flood Control District, California. Soils were sampled from the surface to the first zone of saturation and compared with soils from an adjacent un-contaminated control site. These elements were found to be accumulating in the first few centimeters of basin soil and are important to the effectiveness of a specific best management practice, i.e., the retention and recharge of urban storm water. Study basins in use since 1962, 1965, and 1969 had lead contents in the 0–2 cm soil depth interval‘of 570, 670, and 1400 mg Pb/kg soil, respectively. The median indigenous soil lead concentration was 4.6 mg/kg soil. The practice of removing excess flood runoff water from two basins by pumping apparently is a factor in reducing the accumulation rate of these elements in the surface soils of the basins.     

Trace elements and organochlorines in surf scoters from San Francisco Bay, 1985

Surf scoters (Melanitta perspicillata) were collected from 6 locations in San Francisco Bay during January and March 1985. Overall, mean concentrations of cadmium and zinc were higher in livers of scoters from the southern region of the Bay, whereas mean iron and lead were higher in those from the northern Bay region. Mean concentrations of arsenic, copper, lead, zinc, aluminum (January only) and iron (January) also differed among individual locations. Mean concentrations of copper and zinc increased, arsenic decreased, and cadmium remained the same between January and March. Selenium and mercury concentrations in scoter livers were not significantly correlated (P>0.05), but cadmium concentrations in livers and kidneys were positively correlated (P<0.0001), and body weight was negatively related to mercury concentration in the liver (P<0.05). Body weight differed among locations but not between January and March. Body weight was correlated with lipid content (P<0.0001). DDE and PCBs were each detected in 34 of 36 scoter carcasses. DDE increased significantly between January and March at Richmond Harbor, but BCBs did not differ between January and March at the 3 locations that could be tested.