Plant available phosphorus in soil as predictor for the leaching potential: Insights from long-term lysimeter studies

This study aimed to demonstrate the impact of phosphorus (P) mineral fertilization on topsoil P content and P leaching. We evaluated 83 datasets from 25 years from lysimeter experiments involving different cropping systems (winter crop, summer crop and autumn tillage, harvested grass) or unfertilized fallow, four types of soil texture, and three levels of applied mineral P fertilizer. A positive monotonic and significant correlation was indicated between P in the topsoil determined by the double lactate method (P _DL) and the yearly flow-weight total (TP) concentrations in leachates with Spearman rank correlations r _s (r _s > 0.183) and probability (p) < 0.05. The present German recommended rates of P mineral fertilization are proposed insufficient to protect fresh and marine waters from undesired P pollution and eutrophication. A long-term reduction of excess soil P is urgent along with other measures to mitigate high P inputs to surface and ground waters.     

Comments on 'Elevated antimony concentrations in commercial juices'

The recent J. Environ. Monit. communication 'Elevated antimony concentrations in commercial juices' contains several inaccuracies and misrepresentations about PET packaging as well as food safety and risk assessment. None of the data indicates that "elevated" or unsafe levels of antimony were found in any of the commercial juices or that the variations in antimony levels were attributable to either PET or the other packaging materials.     

Modeling and Predicting Species Occurrence Using Broad-Scale Environmental Variables: an Example with Butterflies of the Great Basin

Abstract: If occurrence of individual species can be modeled as a function of easily quantified environmental variables (e.g., derived from a geographic information system [GIS]) and the predictions of these models are demonstrably successful, then the scientific foundation for management planning will be strengthened. We used Bayesian logistic regression to develop predictive models for resident butterflies in the central Great Basin of western North America. Species inventory data and values for 14 environmental variables from 49 locations (segments of canyons) in the Toquima Range ( Nevada, U.S.A.) were used to build the models. Squares of the environmental variables were also used to accommodate possibly nonmonotonic responses. We obtained statistically significant models for 36 of 56 (64%) resident species of butterflies. The models explained 8–72% of the deviance in occurrence of those species. Each of the independent variables was significant in at least one model, and squared versions of five variables contributed to models. Elevation was included in more than half of the models. Models included one to four variables; only one variable was significant in about half the models. We conducted preliminary tests of two of our models by using an existing set of data on the occurrence of butterflies in the neighboring Toiyabe Range. We compared conventional logistic classification with posterior probability distributions derived from Bayesian modeling. For the latter, we restricted our predictions to locations with a high ( 70%) probability of predicted presence or absence. We will perform further tests after conducting inventories at new locations in the Toquima Range and nearby Shoshone Mountains, for which we have computed environmental variables by using remotely acquired topographic data, digital-terrain and microclimatic models, and GIS computation.     

The OECD validation program of the H295R steroidogenesis assay: Phase 3. Final inter-laboratory validation study

Background, goals, and scope

In response to increasing concerns regarding the potential of chemicals to interact with the endocrine system of humans and wildlife, various national and international programs have been initiated with the aim to develop new guidelines for the screening and testing of these chemicals in vertebrates. Here, we report on the validation of an in vitro assay, the H295R steroidogenesis assay, to detect chemicals with the potential to inhibit or induce the production of the sex steroid hormones testosterone (T) and 17??-estradiol (E2) in preparation for the development of an Organization for Economic Cooperation and Development (OECD) test guideline.

Methods

A previously optimized and pre-validated protocol was used to assess the potential of 28 chemicals of diverse structures and properties to validate the H295R steroidogenesis assay. These chemicals are comprised of known endocrine-active chemicals and ??negative?? chemicals that were not expected to have effects on the targeted endpoints, as well as a number of test chemicals with unknown modes of action at the level of the steroidogenic pathway. A total of seven laboratories from seven countries participated in this effort. In addition to effects on hormone production, confounding factors, such as cell viability and possible direct interference of test substances with antibody-based hormone detection assays, were assessed. Prior to and during the conduct of exposure experiments, each laboratory had to demonstrate that they were able to conduct the assay within the margin of predefined performance criteria.

Results

With a few exceptions, all laboratories met the key quality performance parameters, and only 2% and 7% of all experiments for T and E2, respectively, were excluded due to exceedance of these parameters. Of the 28 chemicals analyzed, 13 and 14 tested affected production of T and E2, respectively, while 11 and 8 did not result in significant effects on T and E2 production, respectively. Four and six chemicals produced ambiguous results for effects on T and E2 production, respectively. However, four of these cases each for T and E2 were associated with only one laboratory after a personnel change occurred. Significant interference of test chemicals with some of the antibody-based hormone detection systems occurred for four chemicals. Only one of these chemicals, however, significantly affected the ability of the detection system to categorize the chemical as affecting E2 or T production.

Discussion and conclusions

With one exception, the H295R steroidogenesis assay protocol successfully identified the majority of chemicals with known and unknown modes of interaction as inducers or inhibitors of T and E2 production. Thus it can be considered a reliable screen for chemicals that can alter the production of sex steroid hormones. One of the remaining limitations associated with the H295R steroidogenesis assay protocol is the relatively small basal production of E2 and its effect on quantifying the decreased production of this hormone with regard to the identification of weak inhibitors. An initial comparison of the data produced in this study with those from in vivo studies from the literature demonstrated the potential of the H295R steroidogenesis assay to identify chemicals affecting hormone homeostasis in whole organisms. Particularly promising was the lack of any false negatives during the validation and the very low number of false positives (1 out of 28 chemicals for each T and E2).

Perspectives

Based on the results obtained during this validation study and the accordingly revised test protocols, an OECD draft test guideline was developed and submitted to the OECD working group of the national coordinators of the test guidelines program (WNT) for comments in December 2009.     

Does quinone or phenol enrichment of humic substances alter the primary compound from a non-algicidal to an algicidal preparation?

Dissolved organic matter (DOM) has been shown to affect phytoplankton species directly. These interactions largely depend on the origin and molecular size of DOM and are different in prokaryotes and eukaryotes. In a preceding study, however, two humic substance preparations did not adversely affect coccal green algae or cyanobacterial growth even at high concentrations of dissolved organic carbon (DOC). These results contradicted previous findings, showing a clear, negative response of different phototrophs to much lower DOC concentrations. To test whether or not at least defined building blocks of humic substances (HSs) are effective algicidal structures, we enriched two humic preparations with hydroquinone and p-benzoquinone, respectively, and exposed two different green algae, Pseudokirchneriella subcapitata and Monoraphidium braunii, and two cyanobacterial species, Synechocystis sp. and Microcystis aeruginosa, to the unmodified and enriched HSs. As response variables, growth rates in terms of biomass increase, chlorophyll-a content, and photosynthetic yield were measured. The highest concentration (4.17 mM DOC) of the modified HSs clearly inhibited growth; the cyanobacterial species were much more sensitive than the green algal species. However, realistic ecological concentrations did not adversely affect growth. Aerating the exposure solution for 24 h strongly reduced the inhibitory effect of the modified HSs. The algicidal effect was obviously caused by monomers and not by polymerised high molecular weight HSs themselves. Furthermore, the maximum quantum yield (Φ PSII max) was stimulated in the green algal species by low and medium DOC concentrations, but reduced in the cyanobacterial species upon exposure to higher HS concentrations. The quinone- and phenol-enriched HSs only showed algicidal activity at high concentrations of 4.17 mM DOC and lost their effects over time, presumably by oxidation and subsequent polymerisation. This study confirms that the applied humic substances themselves are not effective algicides even if enriched in effective structures.     

Evaluation of chlordimeform and degradation products for mutagenic and DNA‐damaging activity in salmonella typhimurium and escherichia coli

Abstract

The mutagenic activity of chlordimeform and two of its breakdown products, 4‐chloro‐o‐toludine and 4‐chloro‐N‐formyl‐o‐toluidine were determined with five histidine dependent strains of Salmonella typhimurium (TA1535, TA1537, TA1538, TA98, TA100) and five tryptophan dependent strains of E. coli WP₂. (WP₂, WP₂uvrA, WP67, CM611, CM571) with and without rat liver microsomal enzymes. 4‐chloro‐o‐toluidine increased the number of the reversions of the S. typhimurium strain TA1535 more than two fold over spontaneous at the concentration of 400 μg/plate.

The results of the DNA repair tests in the Salmonella TA1538/TA1978 and E. coli multirepair deficient systems showed that both breakdown products were active in inducing damage not repaired in at least one repair deficient strain while chlordimeform itself was inactive.     

Contaminant Emissions from the Combustion of Fuels

In the past several years the use of cattle feeding lots for preparing cattle for market has developed into a large industry. These installations extend over much of the United States. Our lot, just outside of Memphis, Tennessee, is at present the only one in the area, but we feel that there will be others soon.

The control of odor in the cattle feeder industry is necessary if the operator does not wish to become the target of a nuisance or injunction suit. In one recent trip extending to Texas, then to California and back, numerous lots were inspected and this paper will present various types of odor control measures which were observed. The problem is one which can be controlled, but it is primarily dependent upon the willingness on the part of management to make the effort.

As a by-product of the cattle feeder lot, large quantities of manure are obtained and unless measures are taken to properly store this material, considerable odor can result. We believe that the use of dehydration in connection with the feeder lot will become more and more necessary, and it is our experience that this type of operation requires: 1. Good design of the dehydrating unit, 2. Careful control of the product flow, 3. An understanding of the proper method for storing the manure prior to its dehydration, and 4. Use of odor control methods to keep down those odors which would constitute nuisance to those living nearby. Various methods of odor control will be discussed.     

A Method for Determining Source Reduction Required to Meet Air Quality Standards

Governmental boundaries which divide our states frequently do not coincide with the natural geographic and atmospheric conditions affecting regional air pollution problems. Moreover, the control regulations of one state may vary from those of its neighbors. Such areal synthesis of air pollution control measures might only minimally curb the difficulties.

Continuity of control will require cooperation among contiguous states. In this study the attitudes of incumbent elected officials and air pollution experts (both from within the Philadelphia metropolitan area) toward governmental responsiveness have been investigated. It was hypothesized that politicians would want to demonstrate a status quo approach while experts would advocate the creation of an environmental agency for the Philadelphia region’s pollution problems. However, both sample groups responded to the questionnaire survey affirming that they want government to establish an environmental regional control agency, based upon an interstate compact, that has authority strong enough to be a strict enforcing agent. This regional agency should meet all federal conditions and thus receive maximum federal financial assistance. The policy level officials of this agency should be appointed experts—so as to avoid partisan politics, and to acquire the most qualified personnel.     

Response

While quality control has been defined and implemented for ambient criteria pollutant monitoring, such as for SO₂, O₃ and total suspended particulates, most of the noncriteria air pollutants currently being measured have not been subject to similar levels of data assurance.. The New Jersey Project on Airborne Toxic Elements and Organic Substances (ATEOS) included the measurement of nearly 50 gaseous and particulate phase noncriteria pollutants, within the structure of a rigorous quality assurance/quality control (QA/QC) program. The following report details the QA/QC results for the particulate and vapor phase pollutants measured during the ATEOS project. Consideration is given to a number of basic differences between measuring inorganic and organic pollutants including method detection limits, number of valid samples, and precision and accuracy of the overall methods. Particular emphasis is placed on how the QA/QC data place limits on statistical analyses of noncriteria air pollutant data sets.     

Estimating fine particulate matter component concentrations and size distributions using satellite-retrieved fractional aerosol optical depth: part 1--method development

We develop a method that uses both the total column aerosol optical depth (AOD) and the fractional AOD values for different aerosol types, derived from Multiangle Imaging SpectroRadiometer (MISR) aerosol data, to estimate ground-level concentrations of fine particulate matter (PM2.5) mass and its major constituents in eastern and western United States. Compared with previous research on linking column AOD with ground-level PM2.5, this method treats various MISR aerosol components as individual predictor variables. Therefore, the contributions of different particle types to PM2.5 concentrations can be estimated. When AOD is greater than 0.15, MISR is able to distinguish dust from non-dust particles with an uncertainty level of approximately 4%, and light-absorbing from non-light-absorbing particles with an uncertainty level of approximately 20%. Further analysis shows that MISR Version 17 aerosol microphysical properties have good sensitivity and internal consistency among different mixture classes. The retrieval uncertainty of individual fractional AODs ranges between 5 and 11% in the eastern United States, and between 11 and 31% in the west for non-dust aerosol components. These results provide confidence that the fractional AOD models with their inherent flexibility can make more accurate predictions of the concentrations of PM2.5 and its constituents.