the internal pressures are in the range of 2 to 5 bar and that operate at temperatures ranging from 700-900 C. The important aspect of the figure is the fact that UV output is a strong function of internal pressure of the lamp generate characteristic wavelengths of a broad spectrum. With conventional mass and energy balance treatment that disconnects the transition between mass and energy such dependence of relative irradiance on pressure cannot be quantified or predicted qualitatively. However, the technique (using the ‘galaxy’ model) proposed by Islam (2014) and later used by Khan and Islam (2016) makes it possible to account for alteration in the subatomic level to be coupled with tangible expression, such as light intensity. The next feature of this figure is the fact that different irradiance level of UV will kill different types of bacteria. Once again, such antibacterial effects can be described with the galaxy model that allows for different wavelengths to destroy different types of bacteria (based on their characteristic length).2
Figure 2.3 Relative output spectra of low- and medium pressure mercury arc lamps in the germicidal UV range. A=2 kW, 100 W/in; B=3.5 kW, 150 W/in; C=5 kW, 150 W/in; D= 6.4 kW, 150 W/in; E=7 kW, 200 W/in (from Blachley III and Peel, 2001).
Knowledge of cinnabar (HgS) is traced back to ancient Assyria and Egypt, but also to China (Wang, 2015). It had value for both medicinal and alchemy applications. In traditional Chinese medicine (TCM), cinnabar has been a high value medicinal component. Wang (2015) pointed out Shennong’s Classic of Materia Medica claims that cinnabar can treat practically all ailments involving the five yang organs3, namely, heart, liver, spleen, lung and kidney. Cinnabar reportedly has calming and revitalizing effects, which help build one’s strength and improve vision, and kill “evil spirits”. The term “evil spirit” has been known to imply inexplicable ailments, including mental illness (Islam et al., 2017). There have been reports of improvement of lungs and hearts owing to ‘moistening actions’ of cinnabar while consumed orally or even applied externally. Most significantly, cinnabar was known to be a cure of convulsion and epilepsy, as well as fetal toxicity and pox virus. It was also considered to prevent malaria (Wang, 2015).
One such compound is mercury sulphide (cinnabar), which is known in ancient Chinese (called zhūshā, 朱砂), Greek and Arabic (called zinjafar,
Cinnabar is generally found in a massive, granular or earthy form and is bright scarlet to brick-red in color, has the highest refractive index of any mineral (King, 2002).
It turns out that mercury compounds continued to be used in Europe during 15th through 20th century. In the era before synthetic antibiotics, sexually-transmitted diseases were of great concern. In search for a cure, various forms of mercury were tried. As such, mercury was the remedy of choice for syphilis in Protestant Europe. Paracelsus (1493-1541) formulated mercury as an ointment because he recognised the toxicity and risk of poisoning when administrating mercury as an elixir. Mercury was already being used in Western Europe to treat skin diseases.
The dominating medical use of Hg, (in metallic form and as calomel, Hg2Cl2), in Sweden in the second half of the 19th century indicates that some persons were highly exposed to Hg, mainly for treatment of syphilis, and 0.3-1% of the population of 3.5-5 millions were treated for venereal diseases (10,000-50,000 patients).
Sublimate (HgCl2) is in certain countries still used as an antiseptic for wounds. It was used in large quantities during the World Wars, triggered by the largely increased use of Hg in explosives. Sublimate was also used for preserving wood.
In the 1830′s, dental restorative material, called ‘amalgam’ was introduced to the United States. This amalgam was developed in England and France and contained silver, tin, copper, zinc and mercury. The amalgam fillings were not openly embraced by organized dentistry in America, and in 1840, members of the American Society of Dental Surgeons were required to sign pledges not to use mercury fillings. By this time, the current methods of refining metals (including mercury) have been in place. Mercury and its compounds used in dental practice may be responsible for release of mercury into the oral cavity. Compounds of mercury tend to be much more toxic than the element itself, and organic compounds of mercury (e.g., dimethyl-mercury) are often extremely toxic and may be responsible in causing brain and liver damage.
Recently, Wang et al. (2013) conducted an interesting study. They orally administered various doses of cinnabar for 10 consecutive days, then studied the mercury levels. They discovered that the mercury level in serum and tissues are significantly higher than that of vehicle control (Table 2.2). The serum mercury levels in the cinnabar groups were increased in a dose-dependent manner. However, the serum mercury content for the cinnabar group was only about 1/100 of that of the HgCl2 group at the same dose. The mercury levels in the brain tissue of the cinnabar group were raised slowly with the increasing dose and were about 1/19 of HgCl2 group at the same dose. Similar to the pattern of the HgCl2 group, mercury accrued more in kidney than in liver. However, in the HgCl2 group, mercury accumulation was about 330 times higher than that of the cinnabar group.
Table 2.2 Mercury contents after cinnabar and HgCl2 administration for 10 days (From Wang et al., 2013).
| Group | Serum (ng/ml) | Brain (ng/g) | Liver (ng/g) | Kidney (ng/g) |
| Vehicle | 1.39 ± 0.05 | 2.96 ± 1.24 | 11.19 ± 4.31 | 14.24 ± 2.97 |
| HgCl2 0.01 g/kg | 401.94 ± 30.3 | 190.25 ± 11.8 | 5571.91 ± 1211 | 23592.40 ± 446 |
| Cinnabar 0.01 g/kg | 4.10 ± 0.47 | 10.63 ± 2.53* | 25.58 ± 5.97 | 70.00 ± 18.02 |
| Cinnabar 0.05 g/kg | 14.63 ± 0.59 | 11.07 ± 2.10 | 32.73 ± 6.96 | 82.69 ± 20.02 |
| Cinnabar 0.1 g/kg | 26.75 ± 6.98 | 12.20 ± 1.44 | 84.75 ± 9.47 | 271.10 ± 49.25 |
| Cinnabar 1 g/kg | 75.30 ± 9.24 | 13.27 ± 2.22 | 89.47 ± 10.02 | 455.88 ± 76.93 |
Meanwhile, there were no significant differences in the tissue distribution patterns between the
