Diurnal Variations in Urinary Mercury Excretion

1984 ◽  
Vol 3 (6) ◽  
pp. 463-467 ◽  
Author(s):  
I.M. Calder ◽  
G.R. Kelman ◽  
H. Mason

A consistent diurnal variation of urinary mercury concentration (expressed as nmol of mercury/mmol of creatinine) has been demonstrated in 36 occupationally exposed workers, the concentration being highest in the morning and lowest in the late evening. This variation is partly intrinsic and partly an artifact because creatinine excretion also varies diurnally, but in the opposite direction. The implications of these findings in relation to the biological monitoring of mercury workers is discussed.

It has long been known that the diurnal variation of the magnetic needle is in an opposite direction in the southern, to what it is in the northern hemisphere; and it was therefore proposed as a pro­blem by Arago, Humboldt and others, to determine whether there exists any intermediate line of stations on the earth where those diurnal variations disappear. The results recorded in the present paper are founded on observations made at St. Helena during the five consecutive years, from 1841 to 1845 inclusive; and also on similar observations made at Singapore, in the years 1841 and 1842; and show that at these stations, which are intermediate between the northern and southern magnetic hemispheres, the diurnal variations still take place; but those peculiar to each hemisphere prevail at opposite seasons of the year, apparently in accordance with the position of the sun with relation to the earth’s equator.


1994 ◽  
Vol 38 ◽  
pp. 587-594
Author(s):  
J. Börjesson ◽  
L. Barregård ◽  
G. Sällsten ◽  
A. Schütz ◽  
R. Jonson ◽  
...  

Abstract In this study we present the results of in vivo measurements of the mercury concentration in organs of occupationally exposed persons by the use of X-ray fluorescence analysis (XRF). The mercury concentration in the right kidney was measured in 20 occupationally exposed workers and 12 referents. The detection limit for the individual persons varied with the kidney depth (mean 26 μg/g, range 12-45 μg/g), was exceeded in nine of the exposed workers but in none of the referents. The mean kidney mercury concentration (including estimated concentration values below the detection limit) was 24 μg/g in the group of exposed workers (group MDC 5 μg/g) and for the group of referents no detectable concentration (mean 1 μg/g) was found (group MDC 6 μg/g). The mean urinary mercury excretions for the two groups were 34 and 1.7 μg per g creatinine. X-ray fluorescence measurements made on liver (n = 10) and thyroid (n = 8), in some of the exposed workers, revealed no measurable mercury concentrations.


Author(s):  
Mohamed Anouar Nouioui ◽  
Manel Araoud ◽  
Marie-Laure Milliand ◽  
Frédérique Bessueille-Barbier ◽  
Dorra Amira ◽  
...  

1872 ◽  
Vol 7 ◽  
pp. 756-758
Author(s):  
J. A. Broun

The author gives the results derived from different discussions of nearly eighty thousand observations, made hourly during the eleven years 1854 to 1864. They are as follows:—1. That the lunar diurnal variation consists of a double maximum and minimum in each month of the year.2. That in December and January the maxima occur near the times of the moon's upper and lower passages of the meridian; while in June and July they occur six hours later, the minima then occurring near the times of the two passages.3. The change of the law for December and January to that for June and July does not happen, as in the case of the solar diurnal variations, by leaps in the course of a month (those of March and October), but more or less gradually for the different maxima and minima.


1984 ◽  
Vol 41 (4) ◽  
pp. 533-538 ◽  
Author(s):  
A Mutti ◽  
M Falzoi ◽  
S Lucertini ◽  
G Arfini ◽  
M Zignani ◽  
...  

2017 ◽  
Vol 37 (9) ◽  
pp. 901-908 ◽  
Author(s):  
AM Samir ◽  
LA Rashed

Aim: The aim of this work was to investigate the relationships between aluminium levels, oxidative status and DNA damage in workers occupationally exposed to aluminium. Subjects and methods: This study was conducted in a secondary aluminium smelter. It included 96 male workers occupationally exposed to aluminium fume and dust compared to 96 male nonexposed individuals. Full history and clinical examination were done for all participants. Laboratory investigations in the form of serum aluminium, total antioxidant capacity (TAC), urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) and comet assay test were performed. Results: Serum aluminium level ranged from 4 to 30 µg/L of median: 10 µg/L; urinary 8-OHdG ranged from 2.7 to 17.2 ng/mg creatinine of median: 7.6 ng/mg creatinine; comet tail length (CTL) ranged from 19.7 to 50.5 µm of median: 45 µm, were statistically significantly increased in the exposed group compared to nonexposed group. In exposed workers, a statistically significant positive correlations were found between serum aluminium level and urinary 8-OHdG ( r = 0.75, p < 0.001); aluminium level and CTL ( r = 0.71, p < 0.001); and urinary 8-OHdG and CTL ( r = 0.71, p < 0.001). There was a statistically significant negative correlation between serum aluminium and TAC ( r = −0.76, p < 0.001). Conclusion: Occupational exposure to aluminium in secondary aluminium smelters was related to the induction of oxidative stress and DNA damage. This may promote the development of adverse health hazards in the exposed workers


2018 ◽  
Author(s):  
Sandy Hardian Susanto Herho ◽  
Dasapta Erwin Irawan

Sonic anemometer observation was performed on 29 - 30 September 2014 in Ledeng, Bandung to see diurnal variations of Turbulence Kinetic Energy (TKE) that occurred in this area. The measured sonic anemometer was the wind velocity components u, v, and w. From the observation result, it can be seen that the diurnal variation that happened was quite significant. The maximum TKE occurs during the daytime when atmospheric conditions tend to be unstable. TKE values were small at night when atmospheric conditions are more stable than during the daytime.


2020 ◽  
Vol 237 ◽  
pp. 03011
Author(s):  
Yasukuni Shibata ◽  
Chikao Nagasawa ◽  
Makoto Abo

We have conducted the measurement of high accurate CO2 mixing ratio profiles by measuring the temperature profiles simultaneously using the three wavelength CO2 DIAL. The measurements of CO2 diurnal variation in the lower atmosphere were carried out on sunny and cloudy days respectively. We find out that increasing of the CO2 mixing ratio occurs over the altitude of about 2 km from the surface during nighttime. On the other hand, the CO2 mixing ratio decreases over the lower atmosphere during daytime. In particular, the CO2 mixing ratio decreases earlier on sunny days than on cloudy days after sunrise. This result suggests that CO2 absorption by photosynthesis greatly contributes to the strength of the solar radiation.


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