Predicting total dissolved solids release from central Appalachian coal mine spoils.

Appalachian USA surface coal mines face public and regulatory pressure to reduce total dissolved solids (TDS) in discharge waters, primarily due to effects on sensitive macroinvertebrates. Specific conductance (SC) is an accurate surrogate for TDS and relatively low levels of SC (300-500 µS cm(-1)) have been proposed as regulatory benchmarks for instream water quality. Discharge levels of TDS from regional coal mines are frequently >1000 µS cm(-1). The primary objectives of this study were to (a) determine the effect of rock type and weathering status on SC leaching potentials for a wide range of regional mine spoils; (b) to relate leachate SC from laboratory columns to actual measured discharge SC from field sites; and (c) determine effective rapid lab analyses for SC prediction of overburden materials. We correlated laboratory unsaturated column leaching results for 39 overburden materials with a range of static lab parameters such as total-S, saturated paste SC, and neutralization potential. We also compared column data with available field leaching and valley fill discharge SC data. Leachate SC is strongly related to rock type and pre-disturbance weathering. Fine-textured and non-weathered strata generally produced higher SC and pose greater TDS risk. High-S black shales produced the highest leachate SC. Lab columns generated similar range and overall SC decay response to field observations within 5-10 leaching cycles, while actual reduction in SC in the field occurs over years to decades. Initial peak SC can be reliably predicted (R(2) > 0.850; p < 0.001) by simple lab saturated paste or 1:2 spoil:water SC procedures, but predictions of longer-term SC levels are less reliable and deserve further study. Overall TDS release risk can be accurately predicted by a combination of rock type + S content, weathering extent, and simple rapid SC lab measurements.

Transformations of nitrogen and carbon in entrenched biosolids at a reclaimed mineral sands mining site.

Biosolids deep-row incorporation (DRI) provides high levels of nutrients to the reclamation sites; however, additions of N in excess of the vegetation requirements can potentially impair water quality. The effects of anaerobically digested (AD) and lime stabilized (LS) DRI biosolids and inorganic N fertilizer were compared on C and N transformations and transport at a reclaimed mineral sands mining site. Biosolids were applied at 213 and 426 Mg AD biosolids ha(-1) and 328 and 656 Mg LS biosolids ha)(-1) (dry mass), and inorganic N fertilizer was applied at 0 (control) and 504 kg N ha-(-1) yr(-1). Zero tension lysimeters were installed to collect leachate for determination of vertical N transport, and the biosolids seams were analyzed for N and C transformations after 28 mo aging. The leachijng masses from the DRI biosolids treatments were 139 to 291 kg ha(-1) NO3-N, 61 to 243 kg ha(-1) NH4-N, and 61 to 269 kg ha(-1) organic N, while the fertilizer treatment did not differ from the control. Aged biosolids analysis showed that total N lost over the course of 2 yr was 15.2 Mg ha(-1) and 10.9 Mg ha(-1) for LS and AD biosolids, respectively, which was roughly 50% of the N applied. Organic C losses were 81 Mg ha(-1) and 33 Mg ha(-1) for LS and AD biosolids, respectively. Our results indicated that entrenchment of biosolids in coarse-textured media should not be used as a mined land reclamation technique because the anaerobic conditions required to limit mineralization and nitrification cannot be maintained in such permeable soils.

Evaluation of leachates from coal refuse blended with fly ash at different rates.

There is great interest in returning coal combustion products to mining sites for beneficial reuse as liming agents. A column study examined the effects of blending two coal fly ashes with an acid-forming coal refuse (4% pyritic S). Both fly ashes were net alkaline, but had relatively low neutralizing capacities. One ash with moderate alkalinity (CRF) was bulk blended with coal refuse at 0, 20, and 33% (w/w), while another lower alkalinity ash (WVF) was blended at 0, 5, 10, 20, and 33% (w/w). The columns were leached (unsaturated) weekly with 2.5 cm of simulated precipitation for >150 wk. Where high amounts of ash alkalinity (>20% w/w) were mixed with the coal refuse, pyrite oxidation was controlled and leachate pH was >7.0 with low metal levels throughout the study. At lower rates of alkalinity loading, trace metals were sequentially released from the WVF ash as the 5, 10, and 20% treatments acidified due to pyrite oxidation. Lechate metals increased in proportion to the total amounts applied in the ash. In this strongly acidic environment, metals such as Mn, Fe, and Cu were dissolved and leached from the ash matrix in large quantities. If ash is to be beneficially reused in the reclamation of acid-producing coal refuse, the alkalinity and potential acidity of the materials must be balanced through the appropriate addition of lime or other alkaline materials to the blend. Highly potentially acidic refuse material, such as that used here, may not be suitable for ash/refuse codisposal scenarios.

An analysis of aerobic capacity in a large United States population.

This study presents a description of aerobic capacity in a large US population comprised of 1,514 men and 375 women. Such influencing factors as age, training state, occupation, and body composition were evaluated. The population consisted of new recruits entering the US Army from civilian life as well as soliders in a variety of assignments and physical training programs. Age ranged from 17 to 55 yr. With the exception of one older group, aerobic capacity was determined as maximal O2 uptake measured directly by the Douglas bag technique during a standard discontinuous treadmill running procedure. New male and female recruits representing a young civilian population entered the service with maximal O2 uptake of 51 and 37 ml X kg body wt-1 X min-1, respectively, and thereafter increased 5% during initial basic training. The difference between genders, 30% on an absolute basis, was 14% when expressed as a function of fat-free weight. Aerobic capacity was less after occupational training and continued to decrease with age at an average yearly rate of 10%, or 0.5 ml X kg body wt-1 X min-1. Aerobic capacity varied with intensity of the occupational physical demand, except in groups with significant physical training programs. This first large US population study of aerobic capacity, using a direct treadmill procedure, demonstrates levels consistent with any previously reported population.

The influence of muscle metabolic characteristics on physical performance.

This study describes the influence of muscle fiber type composition, enzyme activities and capillary supply on muscle strength, local muscle endurance or aerobic power and capacity. Muscle biopsies were obtained from m. vastus lateralis in thirteen physically active men. Histochemical staining procedures were applied to assess the percentage of fast twitch (FT) fibers, muscle fiber area, and capillary density. Also, the activity of citrate synthase (CS), creatine kinase (CK), hexokinase (HK), lactate dehydrogenase (LDH), and phosphofructokinase (PFK) were analysed using fluorometrical assays. Peak torque at 'low' and 'high' angular velocities was measured during leg extension. Similarly, muscle fatigue (e.g. peak torque decline) and recovery from a short-term exercise task were measured during maximal, voluntary consecutive leg extensions. Aerobic power (VO2max) and aerobic capacity (e.g. onset of blood lactate concentration; OBLA), as defined by a blood lactate concentration of 4 mol X 1(-1) were measured during cycling. Peak torque at a high angular velocity was positively correlated with % FT area (p less than 0.001). Fatigue and recovery were correlated with LDH X CS-1 (p less than 0.001). WOBLA was best correlated with PFK and PFK X CS-1 (p less than 0.001). Hence, muscle strength was partly determined by fiber type composition whereas local muscle endurance, recovery and aerobic capacity reflect mainly capillary supply and the activity of key enzymes involved in aerobic and anaerobic metabolism.

Does fever or myalgia indicate reduced physical performance capacity in viral infections?

To study prospectively the effects of a brief febrile viral infection on parameters of muscle and circulatory function, seven volunteers were inoculated with sandfly fever virus and two control subjects with sterile saline. During but not after fever, decreased isometric and dynamic strength and endurance were recorded in various muscles. Impairment could not be explained by altered activities of relevant muscle enzymes in serum or muscle tissue or by altered muscle ultrastructure, but correlated with the severity of perceived symptoms, including myalgia, as rated by each subject. Compared to baseline, cardiac stroke volume was lower during and after fever. During fever, an increased heart rate maintained cardiac output at pre-inoculation values, whereas cardiac output fell in early convalescence. This decrease in cardiac output correlated significantly with the severity of fever. Thus, in brief viral infections a transient impairment of muscle performance capacity is correlated to subjective symptoms such as myalgia, rather than to fever, whereas a decreased cardiac output following such infections seems to be associated with the fever reaction.

Generating productive topsoil substitutes from hard rock overburden in the southern appalachians.

Natural soils on steeply sloping landscapes in the Appalachian coal fields of Virginia. West Virginia. Kentucky, and Tennessee are often thin, rocky, acidic and infertile, making the topsoiling of surface mined sites impractical in many cases. Topsoil substitutes composed of blasted rock fragments are commonly used in this region. The proper selection and placement of designated topsoil substitutes is therefore critical to long term reclamation success. These mine soil surfaces are not in equilibrium and with the surface environment, and it is quite difficult to diferentiate among dissolution, adsorption, desorption and precipitation reactions as these surfaces weather with time. Severe compaction limits the productivity of many otherwise suitable topsoil substitutes. A minimum non-compacted thickness of 1 m is desirable to insure long run mine soil productivity for a variety of post-mining land uses. Significant changes in the physical, chemical, and mineralogical properties of mine soils occur within one year after placement. Mine soils high in silt content often form hard vesicular surface crusts, particularly when left unvegetated. The long term survival of plant communities on these mine soils is dependent upon mine soil organic matter accumulation and N and P cycling. Little is currently known about N and P dynamics in these mine soils, but P-fixation is a profound problem in high Fe(3-) spoils. Revegetation practices that were designed to meet 2-year bond release requirements may not he sufficient to meet new 5-year release standards. Hard rock derived mine soils can often equal or exceed native topsoil in productivity and post mining land use potential.

Effects of travel across time zones (jet-lag) on exercise capacity and performance.

Eighty-one healthy male soldiers, aged 18-34, were studied for 5 d before and 5 d after an eastward deployment across six time zones to determine the effects of translocation on exercise capacity and performance. Fatigue, weakness, headache, sleepiness, irritability, and other commonly reported symptoms occurred in the majority of subjects. Most, but not all, of the symptoms were diminished or absent by the fifth day following the translocation. Cardiorespiratory function and perception of effort during both submaximal and maximal treadmill exercise were unaffected. Isometric strength of the upper torso, legs, and trunk extensor muscles also was not changed. Dynamic strength and endurance of elbow flexors declined significantly. Dynamic knee extensor strength and endurance scores exhibited a progressive decrement prior to translocation and were inconsistent suggesting that the stress of repetitive testing outweighed any jet-lag effects on performance capacity. Performance times for a 270 m sprint were increased for the first 4 d following translocation as were times for a 2.8 km run on the second and third days and for a 110 m lift and carry on the third day after deployment. Times for a 6.5 m rope climb did not change. These findings indicate that certain symptoms and physiological capacities are affected as a result of multiple time zone translocation. However, the specific mechanisms involved, the factors influencing the magnitude of any physiological alterations, and the ultimate impact of these capacity changes on actual physical performance remain to be clarified.

Lactate accumulation in muscle and blood during submaximal exercise.

Muscle and blood lactate concentration was studied in 10 healthy males during cycling exercise. For each subject the exercise intensity corresponding to a blood lactate concentration of 4 mmol.l-1 (OBLAw) was assessed by a step-wise increased exercise intensity protocol. In a second series of experiments the same protocol was performed but exercise was terminated at OBLAw and a muscle biopsy for subsequent analysis of lactate concentration was obtained from m. vastus lateralis. Biopsies were also taken at rest for histochemical determination of fiber type composition and capillary supply. The exercise intensity, which corresponded to OBLAw, averaged 159(117-216) W, equal to 65 (range 55-84)% of VO2max, and was found to be correlated to capillaries per fiber of the exercising muscle (r = 0.83, p less than 0.01). Muscle lactate concentration averaged 6.9 (range 2.1-12.6) mmol.kg-1 w.w. The change in blood lactate concentration (prior to and 1 min post exercise) was correlated to muscle lactate concentration (r = 0.71, p less than 0.05). It is concluded that great individual variations in the muscle/blood lactate gradient do exist during submaximal steady-state exercise, performed at a certain blood lactate level.

The effect of two years' training on aerobic power and muscle strength in male and female cadets.

During their first 2 years of training at the U.S. Military Academy, 11 male and 7 female cadets were studied on five occasions. VO2 max (1/min), lean body mass and body weight increased significantly in both groups. Percent body fat was significantly reduced only after the first summer of training and then returned to initial values. VO2 max (ml/kg.min) did not change in males during the study. However, females increased significantly after the initial 6 weeks of training (44.2 to 48.8 ml/kg.min). They remained at this level through the second summer of training. However, by the end of their second academic year, females' values dropped to 45.9 ml/kg.min. Maximal isometric strength measured 30-40% higher in males than in females. During the last year of training, arm and shoulder strength increased 10.2% in males, but was unchanged in females. Our results suggest that even extended military training did not enable females to significantly narrow the difference with male cadets in muscle strength and aerobic power.

Aerobic power and body fat of men and women during army basic training.

Maximal oxygen uptake (VO2 max) and percent body fat (%BF) were assessed in 87 males and 57 females before and after 7 weeks of Army basic training. VO2 max was determined using a running treadmill protocol and %BF was measured by skinfold technique. VO2 max increased 3.7% (50.7 vs. 52.3 ml/kg.min) and 10.5% (36.9 vs. 39.3 ml/kg.min) for males and females, respectively, with training. %BF decreased 11% in males and 7.1% in females while body weight increased in both. Analysis of variance revealed that, while these changes were significant, there was no quantitative difference in the response of the sexes undergoing the same training program. The data suggest that basic training presents an effective physical challenge for those males and females who have a VO2 max below the ranges of 49-52 ml/kg.min and 38-41 ml/kg.min, respectively, upon entry. In addition, it effectively reduces BF content of those who initially possess high percentages and increases the lean body mass particularly in women.

Physiological effects of a military training program on male and female cadets.

Tested at the beginning and the end of the 6-week training program which all incoming cadets (plebes) undergo upon entering the U.S. Military Academy were 29 males and 26 females (17-21 years old). The aerobic training consisted of running for 30 min 5-6 d/week at varied speeds depending upon performance in an initial 1.5-mile run test. Females responded to training with a significant increase (p is less than 0.001) in VO2 max from 46.0 +/- 1.0 to 49.7 +/- 0.8 ml/kg.min (7.9%). Males did not increase their initial VO2 max (59.4 +/- 1.1 ml/kg.min) significantly. Both groups significantly reduced HRmax and percent body fat. Their initial VO2 max values and activity history accounted for the lack of a significant increase in this highly-fit population of males. Blood lactates were significantly decreased (p is less than 0.05) at the same two submaximal workloads after training. The initial difference in aerobic power between males and females was reduced from 22% to 18%.

Recommendations for the screening of military personnel over 35 years of age for physical training programs.

Persons over 35 years old have an increased prevalence of risk factors. Careful medical examinations, even in a fit military population, are needed before initiating intensive physical training regimens. Risk factor profiling, which synthesizes major risk factors into a composite score, is a beneficial procedure by which to evaluate individuals. Training programs should be based on several considerations: (1) the individual's age and physical condition; (2) his body composition; (3) his risk factor profile; (4) his preference and physical ability for activity; and (5) the available facilities and climatic conditions. Exercise should enhance work capacity and serve as a preventive measure for coronary heart disease. The most efficient types of exercise to meet these ends are activities that involve the large muscles in continuous activity for 20 to 30 min daily, including warm-up and cool-down periods.