Particulate Pb emission factors from wildland fires in the United States

Wildland fires, which includes both wild and prescribed fires, and agricultural fires in sum are one of the largest sources of fine particulate matter (PM2.5) emissions to the atmosphere in the United States (US). Although wildland fire PM2.5 emissions are primarily composed of carbonaceous material, many other elements including trace metals are emitted at very low levels. Lead (Pb) is a US Environmental Protection Agency (EPA) criteria pollutant that is ubiquitous in the environment at very low concentrations including in biomass that can burn and emit Pb into the atmosphere. Although fires may emit Pb at very low concentrations, they can be a source of sizeable Pb emissions to the atmosphere because of the large quantity of PM2.5 emitted from fires. In this work, we measure Pb concentrations in unburned biomass, ash/residues, and particulate matter <2.5 μm (PM2.5) emitted from wildland fires using in-field measurements near prescribed fires and in laboratory simulations. Emission factors were calculated for multiple biomass types, representative of different regions of the US including grasslands in Oregon and Kansas; forest litter from Oregon, Montana, Minnesota, and North Carolina; and peat cores from Minnesota. Most of the biomass Pb remains in the ash/residues. The small percentage (<10%) that is emitted in PM2.5 is dependent on the biomass Pb concentration. The emissions factors measured here are several orders of magnitude lower than some reported in the literature, but the studies exhibited a wide range of values, which may be due to large uncertainties in the measurement method rather than differences in Pb emissions. Wildland fires are expected to increase in size and frequency in future years and these new emission factors can be used to improve the accuracy of Pb emissions estimates and better constrain our understanding of Pb emissions to the atmosphere.

A national survey of lead and other metal(loids) in residential drinking water in the United States

BACKGROUND

Exposure to lead (Pb), arsenic (As) and copper (Cu) may cause significant health issues including harmful neurological effects, cancer or organ damage. Determination of human exposure-relevant concentrations of these metal(loids) in drinking water, therefore, is critical.

OBJECTIVE

We sought to characterize exposure-relevant Pb, As, and Cu concentrations in drinking water collected from homes participating in the American Healthy Homes Survey II, a national survey that monitors the prevalence of Pb and related hazards in United States homes.

METHODS

Drinking water samples were collected from a national survey of 678 U.S. homes where children may live using an exposure-based composite sampling protocol. Relationships between metal(loid) concentration, water source and house age were evaluated.

RESULTS

18 of 678 (2.6%) of samples analyzed exceeded 5 µg Pb L-1 (Mean = 1.0 µg L-1). 1.5% of samples exceeded 10 µg As L-1 (Mean = 1.7 µg L-1) and 1,300 µg Cu L-1 (Mean = 125 µg L-1). Private well samples were more likely to exceed metal(loid) concentration thresholds than public water samples. Pb concentrations were correlated with Cu and Zn, indicative of brass as a common Pb source is samples analyzed.

SIGNIFICANCE

Results represent the largest national-scale effort to date to inform exposure risks to Pb, As, and Cu in drinking water in U.S. homes using an exposure-based composite sampling approach.

IMPACT STATEMENT

To date, there are no national-level estimates of Pb, As and Cu in US drinking water collected from household taps using an exposure-based sampling protocol. Therefore, assessing public health impacts from metal(loids) in drinking water remains challenging. Results presented in this study represent the largest effort to date to test for exposure-relevant concentrations of Pb, As and Cu in US household drinking water, providing a critical step toward improved understanding of metal(loid) exposure risk.

An evaluation of M2+ interference correction approaches associated with As and Se in ICP-MS using a multi-day dataset along with ICP-MS/MS/HR-ICP-MS based analysis and hierarchical modeling as a means of assessing bias in fortified drinking waters and single component matrices

Three 1 2 mass oriented rare earth element (REE) M²⁺ correction approaches (fixed factor, a dual internal standard, and an in-sample) are evaluated for use in an ICP-MS environmental method update. The multi-variant-based evaluation includes analyzing the same 19 REE-fortified matrices on eight different days over a two-month period using two instrument tunes. These REE-fortified matrices were also analyzed using HR-ICP-MS and ICP-MS/MS to estimate the reference value for use in the principal component analysis (PCA) and hierarchical modeling evaluation. A fixed factor is unable to compensate for matrix and mass dependent drift and because of this it generates the largest across matrix, tune, and day 95^th percent confidence bounds for the REE corrections on both As (1.1 ppb) and Se (23 ppb) using samples fortified with 100 ppb Nd, Sm & Gd. The PCA analysis indicated that M²⁺ ions cluster together across matrix, tune and day better than M¹⁺ and these tighter correlations are reflected in reduced 95^th percentile confidence bounds for dual M²⁺ internal standards (M²⁺; As = 0.3 ppb; Se = 5.4 ppb; n = 704) relative to M¹⁺ internal standards (M¹⁺; As = 0.6 ppb; Se = 12.0 ppb; n = 1056). The use of an in-sample M²⁺ correction produced comparable 95^th percent confidence bounds (As = 0.2 ppb; Se = 3.4 ppb; n = 352) relative to the M²⁺ internal standard approaches. Finally, the hierarchical modeling indicated M²⁺ ions as internal standards tend to minimize the across day variability induced by cone changes and the daily reoccurring matrix shifts in the M²⁺/M¹⁺ ratio associated with 250 ppm matrices of Na, Ca, and Mg. This internal standard driven reduction in variability can be beneficial in compliance monitoring methods.

Ambient Particulate Matter and Acrolein Co-Exposure Increases Myocardial Dyssynchrony in Mice via TRPA1

Air pollution is a complex mixture of particulate matter and gases linked to adverse clinical outcomes. As such, studying responses to individual pollutants does not account for the potential biological responses resulting from the interaction of various constituents within an ambient air shed. We previously reported that exposure to high levels of the gaseous pollutant acrolein perturbs myocardial synchrony. Here, we examined the effects of repeated, intermittent co-exposure to low levels of concentrated ambient particulates (CAPs) and acrolein on myocardial synchrony and the role of transient receptor potential cation channel A1 (TRPA1), which we previously linked to air pollution-induced sensitization to triggered cardiac arrhythmia. Female B6129 and Trpa1-/- mice (n = 6/group) were exposed to filtered air (FA), CAPs (46 µg/m3 of PM2.5), Acrolein (0.42 ppm), or CAPs+Acrolein for 3 h/day, 2 days/week for 4 weeks. Cardiac ultrasound was conducted to assess cardiac synchronicity and function before and after the first exposure and after the final exposure. Heart rate variability (HRV), an indicator of autonomic tone, was assessed after the final exposure. Strain delay (time between peak strain in adjacent cardiac wall segments), an index of myocardial dyssynchrony, increased by 5-fold after the final CAPs+Acrolein exposure in B6129 mice compared with FA, CAPs, or Acrolein-exposed B6129 mice, and CAPs+Acrolein-exposed Trpa1-/- mice. Only exposure to acrolein alone increased the HRV high frequency domain (5-fold) in B6129 mice, but not in Trpa1-/- mice. Thus, repeated inhalation of pollutant mixtures may increase risk for cardiac responses compared with single or multiple exposures to individual pollutants through TRPA1 activation.

Analytical considerations associated with implementing M2+ correction factors to address false positives on As and Se within U.S. EPA method 200.8

Rare earth elements (REE) can produce M2+ ions in ICP-MS and 150Nd2+, 150Sm2+, and 156Gd2+ can produce false positives on 75As and 78Se. Alternative instrumental tuning conditions, that utilize lower He flows within the collision cell, reduce these false positives by a factor of 2 (to 0.8 ppb As and 19 ppb Se in solutions containing 50 ppb Nd and Gd) with comparable 16O35Cl+ reduction (<100 ppt false 51V in 0.4% HCl) and Se sensitivity (DL < 1 ppb). Further reduction of these false positives is achieved by estimating the M2+ correction factors and utilizing them in the interference-correction software. Approaches to estimating the M2+ correction factor were evaluated with an emphasis on techniques that tolerate daily variability in end-user backgrounds and their ability to reduce the initial and ongoing purity requirements associated with the rare earth standards used to estimate the M2+ correction factor. The direct elemental and polyatomic overlaps associated with unit-mass approaches tend to overcorrect as non-rare-earth signals as small as 30 cps at the unit mass can induce bias relative to the <300 cps signals associated with the M2+ from a 50 ppb REE standard solution. Alternatively, shifting the M2+ estimate to a half mass (i.e., m/z 71.5: 143Nd2+) eliminates the direct overlap source of bias and allows the unit mass signal to approach 150000 cps before it bleeds over on the 1/2 mass because of abundance sensitivity limitations. The performance of the half-mass approach was evaluated in reagent water and regional tap waters fortified with Nd, Sm, and Gd at 2 ppb and 50 ppb. In addition, a half-mass in-sample approach was also evaluated. This approach was found to be beneficial relative to the external or fixed-factor half-mass approach as it could compensate for instrument drift and matrix-induced shifts in the M2+ factors. Finally, all results were evaluated relative to the As and Se concentrations determined using an ICP-QQQ in mass shift mode and a high-resolution ICP-MS.

Cardiac effects of seasonal ambient particulate matter and ozone co-exposure in rats

Background

The potential for seasonal differences in the physicochemical characteristics of ambient particulate matter (PM) to modify interactive effects with gaseous pollutants has not been thoroughly examined. The purpose of this study was to compare cardiac responses in conscious hypertensive rats co-exposed to concentrated ambient particulates (CAPs) and ozone (O₃) in Durham, NC during the summer and winter, and to analyze responses based on particle mass and chemistry.

Methods

Rats were exposed once for 4 hrs by whole-body inhalation to fine CAPs alone (target concentration: 150 μg/m³), O₃ (0.2 ppm) alone, CAPs plus O₃, or filtered air during summer 2011 and winter 2012. Telemetered electrocardiographic (ECG) data from implanted biosensors were analyzed for heart rate (HR), ECG parameters, heart rate variability (HRV), and spontaneous arrhythmia. The sensitivity to triggering of arrhythmia was measured in a separate cohort one day after exposure using intravenously administered aconitine. PM elemental composition and organic and elemental carbon fractions were analyzed by high-resolution inductively coupled plasma–mass spectrometry and thermo-optical pyrolytic vaporization, respectively. Particulate sources were inferred from elemental analysis using a chemical mass balance model.

Results

Seasonal differences in CAPs composition were most evident in particle mass concentrations (summer, 171 μg/m³; winter, 85 μg/m³), size (summer, 324 nm; winter, 125 nm), organic:elemental carbon ratios (summer, 16.6; winter, 9.7), and sulfate levels (summer, 49.1 μg/m³; winter, 16.8 μg/m³). Enrichment of metals in winter PM resulted in equivalent summer and winter metal exposure concentrations. Source apportionment analysis showed enrichment for anthropogenic and marine salt sources during winter exposures compared to summer exposures, although only 4% of the total PM mass was attributed to marine salt sources. Single pollutant cardiovascular effects with CAPs and O₃ were present during both summer and winter exposures, with evidence for unique effects of co-exposures and associated changes in autonomic tone.

Conclusions

These findings provide evidence for a pronounced effect of season on PM mass, size, composition, and contributing sources, and exposure-induced cardiovascular responses. Although there was inconsistency in biological responses, some cardiovascular responses were evident only in the co-exposure group during both seasons despite variability in PM physicochemical composition. These findings suggest that a single ambient PM metric alone is not sufficient to predict potential for interactive health effects with other air pollutants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12989-015-0087-3) contains supplementary material, which is available to authorized users.

Near-road modeling and measurement of cerium-containing particles generated by nanoparticle diesel fuel additive use

Cerium oxide nanoparticles (nCe) are used as a fuel-borne catalyst in diesel engines to reduce particulate emissions, yet the environmental and human health impacts of the exhaust particles are not well understood. To bridge the gap between emission measurements and ambient impacts, size-resolved measurements of particle composition and mass concentration have been performed in Newcastle-upon-Tyne, United Kingdom, where buses have used an nCe additive since 2005. These observations show that the noncrustal cerium fraction thought to be associated with the use of nCe has a mass concentration ∼ 0.3 ng m(-3) with a size distribution peaking at 100-320 nm in aerodynamic diameter. Simulations with a near-roadway multicomponent sectional aerosol dynamic model predict that the use of nCe additives increases the number concentration of nuclei mode particles (<50 nm in diameter) while decreasing the total mass concentration. The near-road model predicts a downwind mass size distribution of cerium-containing particles peaking at 150 nm in aerodynamic diameter, a value similar to that measured for noncrustal cerium in Newcastle. This work shows that both the emission and atmospheric transformation of cerium-containing particles needs to be taken into account by regional modelers, exposure scientists, and policymakers when determining potential environmental and human health impacts.

Cardiopulmonary toxicity of peat wildfire particulate matter and the predictive utility of precision cut lung slices

Background

Emissions from a large peat fire in North Carolina in 2008 were associated with increased hospital admissions for asthma and the rate of heart failure in the exposed population. Peat fires often produce larger amounts of smoke and last longer than forest fires, however few studies have reported on their toxicity. Moreover, reliable alternatives to traditional animal toxicity testing are needed to reduce the number of animals required for hazard identification and risk assessments.

Methods

Size-fractionated particulate matter (PM; ultrafine, fine, and coarse) were obtained from the peat fire while smoldering (ENCF-1) or when nearly extinguished (ENCF-4). Extracted samples were analyzed for chemical constituents and endotoxin content. Female CD-1 mice were exposed via oropharyngeal aspiration to 100 μg/mouse, and assessed for relative changes in lung and systemic markers of injury and inflammation. At 24 h post-exposure, hearts were removed for ex vivo functional assessments and ischemic challenge. Lastly, 8 mm diameter lung slices from CD-1 mice were exposed (11 μg) ± co-treatment of PM with polymyxin B (PMB), an endotoxin-binding compound.

Results

On an equi-mass basis, coarse ENCF-1 PM had the highest endotoxin content and elicited the greatest pro-inflammatory responses in the mice including: increases in bronchoalveolar lavage fluid protein, cytokines (IL-6, TNF-α, and MIP-2), neutrophils and intracellular reactive oxygen species (ROS) production. Exposure to fine or ultrafine particles from either period failed to elicit significant lung or systemic effects. In contrast, mice exposed to ENCF-1 ultrafine PM developed significantly decreased cardiac function and greater post-ischemia-associated myocardial infarction. Finally, similar exposures to mouse lung slices induced comparable patterns of cytokine production; and these responses were significantly attenuated by PMB.

Conclusions

The findings suggest that exposure to coarse PM collected during a peat fire causes greater lung inflammation in association with endotoxin and ROS, whereas the ultrafine PM preferentially affected cardiac responses. In addition, lung tissue slices were shown to be a predictive, alternative assay to assess pro-inflammatory effects of PM of differing size and composition. Importantly, these toxicological findings were consistent with the cardiopulmonary health effects noted in epidemiologic reports from exposed populations.

High performance liquid chromatography–tandem mass spectrometry (HPLC/MS/MS) assay for chiral separation of lactic acid enantiomers in urine using a teicoplanin based stationary phase

A novel method for the separation and simultaneous determination of urinary D- and L-lactic acid enantiomers by high performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS) is presented. The chiral separation was optimized on a Chirobiotic teicoplanin aglyocone (TAG) column. Most interestingly, the addition of water in small volume fraction to the polar organic mobile phase was found to significantly improve the chromatography. Calibration curves were linear (r2>0.9950) over the range 3-1000 mg/L for L-lactic acid and 0.5-160.8 mg/L for D-lactic acid. The limit of detection (LOD) (S/N=3) and limit of quantification (LOQ) (S/N=10) were determined experimentally (n=3) to be 0.2 and 0.5mg/L for L-lactic acid and 0.4 and 1.3 mg/L for D-lactic acid, respectively. The normal patient range of L-lactic acid was 1-20 microg/mg creatinine with an elevated value of 85 microg/mg creatinine. For D-lactic acid, the range of normal values were between 0 and 5 microg/mg creatinine with an elevated value of 40 microg/mg creatinine. Finally, the validated method allows for rapid analysis with a total run time of 7.5 min.

A simple and selective method for the measurement of leucine and isoleucine from plasma using electrospray ionization tandem mass spectrometry

An analytical method was developed for the rapid and accurate quantification of leucine (LEU) and isoleucine (ILE) from plasma using electrospray ionization tandem mass spectrometry (ESI-MS/MS). The two isomeric amino acids were selectively detected using fragment ions unique to each compound. As a result, the need for chromatographic separation was avoided allowing for faster analysis (3 min). The possibility of any considerable interference between the two transitions was closely monitored, with no significant interference being observed. The presence of interfering compounds in plasma was also evaluated and found to minimal. The method was evaluated based upon linearity, with r2>or=0.995 for both compounds, and accuracy, with no more than 8% deviation from the theoretical value.

[The effect of low temperatures on biochemical indicators in the blood of calves]

Twenty calves, heifers of the Holstein-Friesian breed and crossbreds with the Slovak Pied breed, were divided into two groups at the average age of 19 days. The trial group was kept outdoors in wooden hutches and the control group was housed in an insulated building. Blood was sampled at the age of 20, 33, 48 and 60 days at the outdoor temperatures of 3 degrees C, -2 degrees C, -5 degrees C and -8 degrees C. The calves kept in hutches where temperatures were always lower than in the insulated calf-house had the higher level of nonesterified fatty acids in all observations. The largest, highly significant difference was determined at the age of 60 days at the outdoor temperature of -8 degrees C (271 mumol/l vs. 224 mumol/l), and the significance of differences was also observed in the first and third blood samplings at the temperatures of 3 degrees C and -5 degrees C. The differences were highly significant in the first group between the first and fourth, and second and fourth samplings. In the calves kept in the insulated building the difference was significant between the first and fourth observation because the content of free fatty acids was also gradually increasing in this case (Tab. I). Glycaemia values were also higher in the calves kept in hutches (Tab. II). The most noticeable (significant) difference was determined at the age of 48 days at the outdoor temperature of -5 degrees C (4.3 mmol/l vs. 3.9 mmol/l). Significant differences within the group were recorded only in calves from the trial group kept in hutches. Insulin concentrations increased gradually with the older age of animals (Tab. II). At the age of 20 days the values were identical in fact in both groups and the highest concentrations were recorded at the age of 60 days. The differences between the groups were not significant, the largest difference was observed at the end of milk feeding period at the age of 60 days (19 microUI/l in calves from hutches and 15.6 microUI/l in calves from the insulated building). Triiodothyronine concentrations decreased from the starting values of 0.8 nmol/l and 0.76 nmol/l in both groups at the age of 33 days to the values of 0.61 and 0.62 nmol/l.(ABSTRACT TRUNCATED AT 400 WORDS)

[The effect of high-dose ultraviolet irradiation on sodium, calcium and aldosterone in the blood of calves]

Five Holstein-Friesian calves, from one sire, with prevalent black hair coat pigmentation were used in the experiment. The mean age was 33 days and the mean live weight 51 kg. The animals were exposed free running without interruption for 12 hours to an artificial ultraviolet light in the range of 280-320 nm. The mean doses of radiation was 179.10(-10) J/h/m. One-spot high-pressure mercury discharge lamps Tesla RVK 400 W were used as a radiation source. The dose rate was estimated from measurements by a spectral photometer with filter UG 2 for absorbtion of visible light located at the height of the back of standing calf. Blood samples were collected immediately before the beginning of treatment and after 5, 12, 24, 48 and 72 hours. The blood plasma aldosterone was measured by radioimmunoassays, the levels of sodium, potassium and calcium in blood plasma by flame spectrophotometry. Double classification variance analysis and evaluation according to the Snedecor F-test, the contrast effect test according to Duncan and regression analysis were used for statistical evaluation. Compared to the first sampling, sodium increased significantly after 5 and 12 hours of exposure (Tab. I) to 138.1 and 138.3 mmol/l, respectively. In the subsequent samplings this trend continued up to 72 hours from the beginning of irradiation (140.5 mmol/l). The potassium level did not change statistically significantly. Owing to an excessive irradiation, the calcium concentration increased significantly. The greatest increase occurred after 12 hours of irradiation (from 2.29 mmol/l to 2.61 mmol/l) and after 36 hours from the end of irradiation (2.70 mmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

[The health status and metabolic indicators in calves fed colostrum and first milk preserved with potassium sorbate and milk replacements]

The aim of the experiments was to investigate the effects of the preservation of colostrum and unripe milk with potassium sorbate at a concentration of 0.5% and of its storage for three to five days at normal environmental temperatures on the calf health condition. A set of 30 calves divided into two groups was included in the trial. Calves belonging to the experimental group were fed preserved colostrum and unripe milk from day 9 to day 30 of their life (the first experimental period), and from day 31 to day 50 (the second experimental period) milk replacer. Calves belonging to the control group were fed milk replacer from day 9 to day 50 of their life. One calf from the experimental group died from a respiratory disease. In the control group, one calf died and another had to be slaughtered; in both cases digestive tract diseases were diagnosed. The number of calves which had to be treated medically was also lower in the experimental group--in the calves fed preserved colostrum--one case of periodic tympany was recorded in comparison with four cases in the control group. When haematological and biochemical characteristics were examined, significantly lower haemoglobin levels were found in experimental calves at the end of the first experimental period (105.4 g.l-1 when compared with 112 g.l-1 in the control group) and significantly higher values of proteinaemia were found in the blood plasma of these calves at the same period (59.6 g.l-1 and 53.8 g.l-1, respectively). Similar differences were also found during a single haematological and biochemical examination.

[The effect of excessive artificial UV radiation on the measurement of blood parameters and phagocytosis in calves]

5 calves of an age of 33 days were exposed to UV-light (280-320 nm) for a time of 12 hours. The mean dose of radiation was 179 x 10(-10) J/h x m-2. The results show slight influences of overdosed radiation on hemoglobin content of the blood, from 105.1 g/l to 102.6 g/l. The mean content of hemoglobin in erythrocytes decreased: 364 g/l to 347 g/l. The total leucocytes decreased from 7.74 x 10(9)/1 to 7.08 x 10(9)/1 after exposition of 5 hours. The exposition increased lymphocytes (55.6% to 66.0%) and decreased neutrophils (43.6% to 33.8%). The relationship of lymphocytes to neutrophils extended even after radiation time of only 5 hours from 1.45 to 2.04. The phagocytotic activity increased after 5 hours of exposition. To the end of exposition (60 hours after observation) a decrease was observed. A correlation between doses of radiation and hematological changes was found after 12 hours of radiation in lymphocyte counts (r = 0.878) and neutrophil counts (r = -0.824) as well as in the relation of lymphocytes to neutrophils counts (r = 0.941) and in the index of phagocytosis (r = 0.804).

[The effect of artificial ultraviolet light on biochemical indicators in calves]

Changes in the biochemical parameters of the blood serum of calves were studied after exposure to optimum doses of ultraviolet radiation. The calves were exposed to UV-light twice daily in three periods: 8, 9 and 10 days. Daily doses of 90, 130 and 180 mEr.h.m-2 were used in the first experiment, 120, 180 and 240 mEr.h.m-2 in the second experiment. As found, exposure to radiation in the individual periods increased total proteinaemia, the differences between the experimental and control groups being significant. Exposure to ultraviolet light induced an increase in the activity of the thyroid gland; at the end of the periods of UV-radiation the concentration of thyroxine in the experimental groups was significantly or highly significantly higher. The largest differences were recorded in the first trial (15 nmol per litre to 21.4 nmol per litre). No changes were detected by the evaluation of the activities of alkaline phosphatase, triiodothyronine, sodium, potassium and calcium and in the sodium: potassium ratio.

[Changes in biochemical indicators in dairy cows induced by extremely low temperatures]

The objective of the experiment was to find out the effect of extremely low temperatures on the biochemical characteristics of the cows. Twenty-one dairy cows were used as the experimental material. The experimental group (n = 12) was kept loose in an open barn without thermal insulation and the control group (n = 9) was kept in an insulated cow-house. The winter season included two periods of extremely low temperatures: from the 3rd to the 21st of January 1985 the average minimum temperature in the open barn was -12.6 degrees C and the lowest temperature was -19 degrees C, and in the period from the 8th to the 20th of February 1985 the average minimum temperature was -13.1 degrees C and the lowest recorded temperature was also -19 degrees C. At the beginning of hypothermic stress, the concentration of non-esterified acids and total proteins increased in the cows of the experimental group; potassiaemia was decreased in this group. Cholesterolaemia and glycaemia increased during the long-continued exposure to low temperatures. The activity of the thyroid gland was increased at all measurements.

[The effect of extreme temperatures on hematologic and biochemical indicators in heifers]

The study was aimed at finding the effect of low and high temperatures on some biochemical parameters in heifers. Thirty half-sister heifers were used as the experimental material. The animals were divided into two groups. The experimental group including 16 heifers was kept loose on deep litter in an open barn with no thermal insulation. The control heifers (n = 14) were kept in a thermally insulated house. Blood was collected at extreme temperatures: above 30 degrees C and below -5 degrees C. An insignificant decrease of haemoglobin and haematocrit was recorded in the blood collected at low and high temperatures from the heifers kept in the open barn; a reduction of cholesterolaemia and total lipaemia was recorded at high temperatures. High and low temperatures significantly increased the concentration of free amino acids; the differences between the experimental and control group being from 36 to 76 mumol per litre. The content of 3.5-cyclic adenosine monophosphate was increased insignificantly at extreme temperatures. Hyperglycaemia was recorded in the heifers at high temperatures and at the beginning of the winter season. At low temperatures the concentration of thyroxine was found to be increased in the blood of the experimental animals: 120 nmol per litre and 161 nmol per litre vs. 95 nmol and 116 nmol in the control group.

[The effect of prolonged movement restriction of dairy cows on biochemical parameters]

In thirty-three dairy cows--first calves, the influence of hypokinesis on biochemical parameters was studied over three lactation periods. The cows of the experimental group (n = 15) were reared in steel cages enabling only minimum movement, whereas the control group (n = 18) was housed loosely. It was found out that the permanent movement restriction led to a statistically significant decrease in hemoglobin and hematocrit concentrations, as well as in aspartate aminotransferase activity. In comparison with the control group, a significant decrease was also observed in substances of the lipid group--cholesterol, triglycerides and total lipids. Similarly, thyroxin and total proteinemia were lower.