The Serum Levels of the Heavy Metals Cu, Zn, Cd, and Pb and Progression of COPD-A Preliminary Study.

There is evidence in previous studies that high levels of heavy metals may play a key role in the development of COPD due to the induction of chronic inflammation and oxidative stress. In this preliminary study, we used atomic absorption spectrophotometry to measure the levels of four heavy metals (Cu, Zn, Cd, and Pb) in blood serum of COPD patients and controls over 2 years. Clinical data on disease progression or absence were collected in patients living in the industrial region of Stara Zagora, Bulgaria. The mean values of Cu in the serum of patients with COPD and the control group were 374.29 ± 15.03 µg/L and 238.55 ± 175.31 µg/L, Zn­2010.435 ± 670.006 µg/L and 1672.78 ± 934.27 µg/L, Cd­0.334 ± 0.0216 µg/L and 0.395 ± 0.110 µg/L and Pb­0.0732 ± 0.009 µg/L and 0.075 ± 0.0153 µg/L. This is probably because these elements are biogenic and are used in the body for its anti-oxidant protection. In fact, it cannot be stated with certainty that elevated levels of Cu and Zn in the environment have a negative impact in COPD patients. There was a trend towards higher levels of the toxicants lead and cadmium in COPD patients compared to the control group of patients. There is a statistically unproven trend toward higher levels of lead and cadmium in COPD patients compared to controls, which to some extent supports our hypothesis that there is a relationship between environmental lead and cadmium levels and the COPD manifested. In COPD patients, a positive correlation was found between BMI and serum Cu levels (r = 0.413, p = 0.005). A higher concentration of serum Cu was found in men with BMI ≥ 30, compared to those with BMI < 30. There is also a positive correlation to a lesser extent between CRP and cadmium (r = 0.380; p = 0.019) and lead (r = 0.452; p = 0.004). The correlation of lead and cadmium with PSA also shows that these elements may also be associated with the presence of inflammatory processes. A significant negative correlation exists between Pb in the serum of patients with COPD and their blood hemoglobin (r = −356; p = 0.028). The results of our study suggest that higher doses of the trace elements Cu and Zn do not always have a negative effect in patients with COPD, while the toxicants Pb and Cd may be involved in COPD exacerbation and can be used as prognostic biomarkers for progression. Further studies are warranted to confirm these preliminary results.

Content of Pb and Zn in Sediments and Hydrobionts as Ecological Markers for Pollution Assessment of Freshwater Objects in Bulgaria-A Review.

The purpose of this review is to describe the contents of Pb and Zn in sediments and hydrobionts as ecological markers for the pollution assessment of freshwater objects in Bulgaria, and the data are compared with other countries and regions. Symmetry was found regarding the levels of Zn in the sediment of the Ovcharitsa and Zhrebchevo dams, which were twice the MAC for arable land (Regulation № 3 of Bulgarian legislation). Symmetry was also observed between the results for Zn and Pb in the studied sediments, and the "favorites" in terms of content were the samples from Zhrebchevo Dam and, especially, from Ovcharitsa Dam. Asymmetry was established in the accumulation of Zn in the livers of carps inhabiting Topolnitsa Dam in comparison with these in Ovcharitsa Dam. A similar asymmetry was observed for lead. The analysis of the muscles and livers of the studied fish showed an asymmetry in the accumulation of zinc, and this process was more intense in the liver. Symmetry was found in the accumulation of Pb in the liver and muscle tissues of the carp from the studied water bodies.