An ethnography of low-income mothers' safeguarding efforts

Problem

Children living in lower-income environments are at greater risk for unintentional injuries. However, little is known about the safety practices of mothers living in low-income situations.

Method

This ethnographic study explored the child safeguarding experiences of low-income mothers using in-home interviews and observations.

Results

Mothers' safeguarding efforts included cognitive and emotional work, child directed work, and work directed at the physical and social environments. Factors that influenced the women's safeguarding included the quality of the indoor space, availability of safe play space, traffic hazards, sibling interactions, child care supports, relationships with neighbors, and trust in community services.

Discussion

These findings have implications for the conceptualization of safeguarding practices and provide insight about the experiences of mothers living on low-incomes.

Impact on Industry

When developing safety interventions, program planners should consider the views and practices of mothers as well as contextual factors in the physical and social environments.     

桥式起重机主梁变形分析及其修复方法

分析了桥式起重机主梁变形产生的原因,介绍了在设计和使用中对主梁变形的一般要求,着重阐述了工程实践中主梁变形修复的一些方法。     

Integrated environmental assessment methods: Evolution and applications

The central objectives of the European Forum on Integrated Environmental Assessment (EFIEA) include improving the scientific quality of Integrated Environmental Assessments (IEA) as well as strengthening the interactions between science and policy making in environmental matters. This paper is intended to provide a concise assessment of the evolution of IEA methods and present it as a background to current thinking on and practice in IEA. Historical roots of IEA concepts and applications are explored. Common elements and distinctive features in recent proposals to define IEA are sorted and a liberal definition is proposed for the purposes of the present methodological study. This definition emphasizes the interdisciplinary character and environmental policy orientation of IEAs. Changes in the nature, social perception, and management of environmental problems are identified as the major factors driving methodological development in IEAs. A simple scheme is proposed to arrange the main elements of IEA: disciplinary tools, integration tools, and assessment frameworks. The role of IEAs in environmental management is examined by adopting the concept of risk management functions. Due to the varying needs for interdisciplinary research and diverging degrees of policy involvement across those functions, the potential contribution of IEAs to activities belonging to different functions also varies. The flexibility and diversity of IEAs are demonstrated by a sampler of frameworks that have been developed to address profoundly different problems and audiences. This revised version was published online in July 2006 with corrections to the Cover Date. This revised version was published online in July 2006 with corrections to the Cover Date.     

Evaluation of an Exposure Assay to Measure Uptake of Sediment Pah by Fish

The ecological risks of polynuclear aromatic hydrocarbons (PAH) in aquatic sediments will vary with both toxicity and bioavailability to aquatic biota. While there are standardized protocols to test the acute toxicity of sediment-borne compounds to aquatic invertebrates, there are none for assessing bioavailability to fish. We found that sediment-borne PAH caused an exposure-dependent induction of cytochrome P450 (CYP1A) enzymes in rainbow trout (Oncorhynchus mykiss) fingerlings exposed in semi-static 96 h bioassays, as shown by increased activity of ethoxyresorufin-o-deethylase (EROD). Assuming that PAH are taken up by trout due to partitioning from organic and inorganic constituents of sediments, we tested the effect of different test variables on bioaccumulation using induction as an index of exposure. EROD activity increased with exposure of fish to increasing volumes of sediments containing PAH, i.e., with increasing ratios of sediment to water. Uptake of single compounds from sandy sediments did not differ from uptake from clay or low organic (7% LOI — loss on ignition) sediments, but decreased when organic content was very high (58% LOI). Maximum induction was observed within 24~h of exposure and at 7.5^C relative to 15, 22, or 28^C. Storage and handling techniques had minor effects on sediment EROD induction potency. Absolute EROD activity was greater in white sucker (Catostomus commersoni) a benthic species, than in trout, a pelagic species. However, when basal (negative control) activity was accounted for, there was no difference in response between the species. Together, these experiments provide a basis for developing a standard protocol to test the bioavailability to fish of sediment-borne PAH.     

Improving Efficiency Of Uncertainty Analysis In Complex Integrated Assessment Models: The Case Of The Rains Emission Module

Abstact Ever since the Regional Acidification Information and Simulation Model (RAINS) has been constructed, the treatment of uncertainty has remained an issue of major interest. In a recent review of the model performed for the Clean Air for Europe (CAFE) programme of the European Commission, a more systematic and structured uncertainty analysis has been recommended. This paper aims at contributing to the scientific debate how this can be achieved. Because of its complex structure on the one hand and limited research resources (time, computational capacities) on the other hand a full-blown uncertainty analysis in RAINS is hardly feasible. Therefore, all types of uncertainty require more efficient ways for uncertainty analysis. With respect to parameter uncertainty, we propose to focus research efforts for uncertainty analysis on key parameters. Among different approaches to select key parameters that have been discussed in the literature screening methods seem to be particularly appropriate for complex, deterministic Integrated Assessment models such as RAINS. Surprisingly, in Integrated Assessment modelling for air pollution problems of screening design have not been taken up so far. As a case study we consider the emission module of RAINS. We show that its structure allows for a straightforward and effective screening procedure     

Inter-Laboratory Comparison of No2 and SO2 Generated by Dynamic Dilution System Under Laboratory Conditions: A Technical Discussion

A workshop on analytical quality control (AQC) of ambient air quality measurement methods for nitrogen dioxide (NO₂) and sulphur dioxide (SO₂) was conducted by Central Pollution Control Board (CPCB) for officials involved in National Ambient Air Quality Monitoring (NAAQM) in India. Concentrations of NO₂ and SO₂ were generated by dynamic dilution system under laboratory conditions at low and high levels and measured using static dilution system and wet chemical methods laid down by CPCB under section 16(2)(h) of the air act 1981. CPCB provided the measured values as reference values for comparing the means obtained by the officials participated from thirteen organizations. A tolerance limit of ±15% of the reference values was specified to accept the results. Generated concentrations, which were unknown to the participants, were measured using gaseous sampling assembly (Envirotech APM 411, New Delhi, India), and wet chemical methods laid down by CPCB i.e. the same methodology which is used by the organizations to generate the data of NO₂ and SO₂ in ambient air. Simultaneously, concentrations were checked by CPCB using automatic analyzers as a check on reference concentration. It is observed that results of automatic analyzers for NO₂ and SO₂ were within a tolerance of ±5% with %RSD below 3. On the other hand, results of most of the participants showed variability in the measurements with %RSD ranging between ±0.8 and ±88.6 and exceedences of means from the tolerance limit with bias ranging between 1.4 and −59%. To check the cause of high variability in the measurements obtained under identical conditions, duplicate sampling was performed by one of the participants for SO₂ at low concentration level. In this study, results of wet chemical methods, automatic analyzers and results of duplicate sampling are analysed statistically to assess the cause of high variability in the measurements. Analysis of t-test and analysis of variance (ANOVA) showed highly significant results for NO₂ and SO₂ at high concentration levels (α 0.05) and for SO₂ at both the levels (α 0.01) respectively indicating some bias is existing either in the sampling or in analytical technique. Duplicate sampling performed to check precision in parallel measurements showed high %RSD indicating the presence of systematic error in sampling technique as the same calibration factor (CF) was used to measure the concentration of duplicate samples. Statistical analysis of flow rates of duplicate sampling showed that the sampling assembly could not maintain the constant flow rate within the ±10% with that measured at the start of the sampling. This resulted in high %RSD and deviation from the reference values for the results of most of the participants, even after accepting ±15% tolerance limit. There is a need to improve and evaluate this gaseous sample collection device under laboratory conditions to generate reliable database of NO₂ and SO₂ in ambient air.     

室内甲醛污染与控制

甲醛是室内空气污染的主要污染物之一,本文简单介绍了室内空气中甲醛污染的来源及危害,详细介绍了减少室内甲醛污染的净化措施.     

不同方法制备的铟催化剂选择性还原NO

不同负载量的In/Al₂O₃催化剂分别以浸渍法、共沉淀法和溶胶-凝胶法制得,对比评价了不同方法制备的样品在富氧条件下以丙烯为还原剂,选择性催化还原NO的活性,考察了氧气浓度、H₂O对活性的影响.研究表明,铟催化剂有较高的去除NO活性,制备方法对催化剂活性具有显著影响.其中,溶胶-凝胶法和共沉淀法最高活性都可达90%左右;而浸渍法样品的活性较差,最高转化率不到60%.氧气浓度对NOx最高转化率及其相应反应温度均有重要影响.随着O2浓度的提高,最高活性对应的反应温度降低.反应气氛中H₂O的加入使铟催化剂活性大幅降低.铟与其他多种金属活性组分相比,一个突出的不同表现是,3种方法各自的最佳负载量相差不大.     

水样不同处理方式对总磷监测值的影响

研究了水样不同处理方式对三峡水库长江干流江段总磷监测值的影响.结果表明,悬浮颗粒物浓度(SS)是澄清样和浑样、清样和浑样、清样和澄清样总磷之间差别的主要影响因子;用非线性回归方法得出了水样不同处理方式下总磷间的经验关系式,并进行了验证.结果表明,计算值和实测值基本吻合.依据SS和所得经验关系,可计算磷在水-固两相之间的分配,及磷在粗颗粒物和细颗粒物中的赋存比例.河床上覆水体中溶解态磷、颗粒态磷及赋存于粗颗粒物上的磷所占比例皆随悬浮颗粒物浓度发生显著变化.SS大于500mg·L-1时,90%以上的磷赋存于悬浮颗粒物上,澄清样磷仅代表了整体总磷浓度的50%以下.     

Maximum permissible and negligible concentrations for some organic substances and pesticides

The aim of the paper is to provide interested parties the methods that were used for generic hazard assessment in The Netherlands, and the resulting so-called maximum permissible concentrations (MPCs) and the negligible concentrations (NCs) for approximately 150 organic substances and pesticides. The MPCs and NCs were derived for water, sediment, and soil. The concentration in the environment above which the risk of adverse effects was considered unacceptable to ecosystems is called the MPC. The MPCs take into account that the substances are distributed among the different environmental compartments, and are harmonized accordingly. The MPCs served as a basis for the Dutch government to set generic environmental quality standards (EQS) in The Netherlands (IWINS,[15]). EQS in turn are used by the Dutch Government to assess the environmental quality and for other environmental policy purposes. Concentrations in the environment below which the occurrence of adverse effects is considered to be negligible are called NCs. Hazards must be reduced when the environmental concentration of a substance exceeds its MPC. In-between this limits reduction of hazards is preferable. The MPC is a scientifically derived hazard limit. The NC is simply defined as 1% of the MPC. In general, there is a great demand for ecotoxicological data that currently limits a more reliable estimate of many MPCs. For water, approximately half of the MPCs are derived on the basis of four or more NOECs (no observed effect concentrations). For the other half, MPCs are based on only a few chronic or acute tests. For soil and sediment, however, almost no ecotoxicological data are available, and MPCs for those compartments have, in many cases, been derived from MPCs in water applying the equilibrium partitioning method (EqP-method), resulting in MPCs with greater uncertainty. Some of the methods and underlying assumptions that have been used may need improvement. For example, the factor between MPC and NC, the statistical extrapolation method, the method that is used for secondary poisoning, the role of the background concentrations of ‘naturally’ occurring substances, and the bioavailability and the EqP-method. There is a great need for hazard limits, and the present compilation tries to provide those as well as identifying research gaps.