Estimated Variability of National Atmospheric Deposition Program/Mercury Deposition Network Measurements Using Collocated Samplers

The National Atmospheric Deposition Program/Mercury Deposition Network (MDN) provides long-term, quality-assured records of mercury in wet deposition in the USA and Canada. Interpretation of spatial and temporal trends in the MDN data requires quantification of the variability of the MDN measurements. Variability is quantified for MDN data from collocated samplers at MDN sites in two states, one in Illinois and one in Washington. Median absolute differences in the collocated sampler data for total mercury concentration are approximately 11% of the median mercury concentration for all valid 1999–2004 MDN data. Median absolute differences are between 3.0% and 14% of the median MDN value for collector catch (sample volume) and between 6.0% and 15% of the median MDN value for mercury wet deposition. The overall measurement errors are sufficiently low to resolve between NADP/MDN measurements by ±2 ng·l⁻¹ and ±2 μg·m⁻²·year⁻¹, which are the contour intervals used to display the data on NADP isopleths maps for concentration and deposition, respectively.     

Attitude Towards Risk and Production Decision: an Empirical Analysis on French Private Forest Owners

This paper deals with the forest owner’s attitude towards risk and the harvesting decision in several ways. First, we propose to characterize and quantify the forest owner’s attitude towards risk. Second, we analyze the determinants of the forest owner’s risk attitude. Finally, we determine the impact of the forest owner’s risk attitude on the harvesting decision. The French forest owner’s risk attitude is tackled by implementing a questionnaire, including a context-free measure borrowed from experimental economics. The determinants of the forest owner’s risk attitude and harvesting decision are estimated through a recursive bivariate ordered probit model. We show that French forest owners are characterized by a relative risk aversion coefficient close to 1 with a DARA assumption. In addition, we find that the forest owner’s risk aversion is influenced positively and significantly by the level of risk exposure, the geographical location of the forest and the fact to be a forester, and negatively by the income. Finally, we obtain that the forest owner’s risk aversion has a positive and significant impact on the harvesting decision.     

Evaluation of a four year intervention to reduce musculoskeletal hazards among berry growers

PROBLEM: Fresh market berry production workers are exposed to physical risk factors for musculoskeletal injury. METHOD: We disseminated information through trade publications and other sources to berry managers in seven U.S. states about five prevention through design practices that were both safer and more profitable than traditional methods. We administered mail evaluation questionnaires prior to the intervention and after each of four intervention years to rolling, independent U.S. samples and to comparison New Zealand berry farm manager samples after years one through three. RESULTS: U.S. manager self-reports of reading trade publication information increased compared to baseline values for two of five practices and self-reported awareness increased for four of five practices. There were no increases in adoption. More U.S. than New Zealand managers reported getting information about two practices from trade publications and about four practices from public events. No U.S. versus New Zealand differences were observed in reported awareness or adoption for any practice. IMPACT ON INDUSTRY: This study showed that even a modest campaign can build awareness of safer practices fairly quickly in three to four years among small agricultural firms but that increasing adoption apparently requires more time. Widespread adoption of safer practices could help keep operators in business longer as they age by reducing the workload and musculoskeletal strain associated with labor intensive crop production for them and their workforce. Adoption of practices that also improve profits, like the five practices featured in this study, could also help managers stay in business.     

Development of an objective determination of a slip with a portable inclineable articulated strut slip tester (PIAST)

A portable inclineable articulated strut slip tester (PIAST) is a slipmeter that is widely used in the USA to measure coefficient of friction (COF) at the shoe sole and floor interface. A determination of a slip at the measurement interface, which is currently judged subjectively by operators, plays a crucial role in deciding the outcomes of a PIAST measurement. The goal of this study was to develop an objective determination of a slip based on the movement of the weight used by the slipmeter. The displacement of the weight and the time duration of consecutive strikes in a measurement were used to derive the objective slip criterion. Various footwear materials, floor materials and surface conditions were used to cover a wide range of COF values. The results of the regression analysis indicated that the objective COF predicted by the method developed in the current study was significant (R² = 0.997, β = 0.991, p < 0.001) in predicting the subjective COF determined by the operator.