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Macromolecular contrast agents are very attractive to afford efficient magnetic resonance imaging (MRI) visualization of implantable medical devices.

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A series of thermally stable organic polymers [poly(2,5-diethynylpyridine] (5), [poly(1,4-diethynyl benzene)] (6), [poly(2,5-dialkyl-p-phenyleneethynylene)] (7), and [poly(p,pdiethynylbiphenyl)] (8), were synthesized by the reaction between diterminal aryleneethynylene, [HCCArCCH] {Ar = C 5 H 5 N (1); Ar = C 6 H 6 (2); Ar = C 6 H 4 (CH 3 ) 2 (3); Ar = C 6 H 4 −C 6 H 4 (4)} and CuCl in pyridine by Hay's oxidative coupling method. Then the organometallic polymers [Ph (P n Bu 3 ) 2 Pt−C≡C−(Ar−C≡C−C≡C) n −Pt((P n Bu 3 ) 2 Ph] {Ar = C 5 H 5 N (9); Ar = C 6 H 6 (10); Ar = C 6 H 4 (CH 3 ) 2 (11); Ar = C 6 H 4 −C 6 H 4 (12)} were synthesized by the reaction of organic polymers 5, 6, 7 and 8 with metal precursor (P n Bu 3 ) 2 PtPhCl in diethylisopropileamine with good yield. These metal-linked polymers were characterized by IR, 1 H-NMR, 13 C-NMR and 31 P-NMR spectra. Finally the molecular weight of the organometallic polymers (9, 10, 11 and 12) was determined by gel permeation chromatography (GPC). It is clearly observed from GPC that the polymers were synthesized with different degree of polymerization.

Knowledge of toxic metal concentrations in meat products is important for assessing their risk on health when consumed. Levels of such metals have neither been questioned, nor the appropriate total dietary studies (TDS) have ever been conducted in Lebanon to carry out proper risk assessments. The study reports on the levels of lead (Pb) and cadmium (Cd) in canned and processed meats sold in the north. 75 brands of canned and 33 of processed meats were purchased from local markets. Digested samples were analysed using graphite furnace atomic absorption spectroscopy (GFAAS) to determine the metals' concentrations. All samples were analysed in triplicate and included blanks and certified reference material (CRM) to validate the analysis. 46 samples (61%) of the canned showed levels of Pb ranging from 0.2 to 816.1µg/kg while 68 samples (91%) showed Cd levels ranging from 0.19 to 138.3µg/kg. For the processed, 91% of the samples revealed Pb levels ranging from 0.245 to 61.3µg/kg, while 97% tested positive for the presence of Cd in the range of 0.02 to 29.7µg/kg. In general, processed meats were found to have lower concentrations of both metals, whereas canned meats posed the greater risk. In comparison with the provisional tolerable weekly intake levels (PTWI), data showed that adults almost reached the set PTWIs for a number of samples, whereas children, have markedly exceeded such values, sometimes by 186%. Data suggests that immediate action should be taken to carry out comprehensive TDS and risk assessment studies.

Meat is widely considered to be a good source of protein, vitamins and minerals such as iron, selenium, zinc, vitamin B. Besides consuming meat muscle tissues, it is well known that in the Mediterranean area certain populations also consume other meat tissues as the bone marrow, fats, and what is known as "Fashi" or "Ma'alak" which contains the kidneys, spleen, liver, heart, and lungs. In addition, muscle, liver and kidney tissues of such organisms are widely consumed raw, without any further processing. The risk arises from the fact that such meat products are obtained from organisms which in turn have accumulated toxic metals in their tissues. Therefore, levels of lead (Pb) and cadmium (Cd) from various fresh meat tissues of beef, goat and lamb have been determined in Lebanon for the first time. Their inter-and intra-levels distribution were assessed and compared. Their potential exposure risk from dietary intake was also studied. A total of two hundred and forty (n=240) samples of fresh meat tissues (80 beef, 80 goat and 80 lamb) were collected over a period of several months from various slaughter houses. From each type of organism, five samples of nclusion tissues (heart, liver, fat, muscle, lung, kidney, bone marrow and spleen) were taken. Each individual sample was then subdivided into subsamples for subsequent analysis and quality control purposes. High-pressure closed vessel acid-assisted microwave digestion was used to digest all samples while graphite furnace atomic absorption spectroscopy was used for the quantification of the toxic metals. The data showed that the mean levels of Pb in goats ranged from 2.66 to 69.84 µg/Kg for the various tissues studied. In beef, they ranged from 0.50 to 41.34 µg/Kg. While in lamb, levels ranged from 1.59 to 95.95 µg/Kg. Meanwhile, the levels for Cd ranged from 2.39 to 635.86 µg/Kg for goat, 0.55 to 173.72 µg/Kg for beef, and 1.37 to 688.95 µg/Kg for lamb. Based on the inter- This paper is part of the Proceedings of the 3 International Conference rd on Environmental and Economic Impact on Sustainable Development (EID 2016) www.witconferences.com level distribution of Pb and Cd in various tissues, beef meat tissues were found to have lower levels than lamb or goats. These findings suggest that consuming beef meat tissues is much safer due to less exposure to such metals. For the intralevel distribution of Pb in goats, the spleen, kidney and liver were found to have the highest levels. The same pattern was also found for beef and lamb. As for cadmium, the data was clear in showing that in all three types of organisms and within each of their tissues, the liver and the kidneys accumulated noticeably high amounts as opposed to their other tissues. In comparison to the maximum allowable levels (MAL) for Pb and Cd in meat (100 and 50 µg/kg, respectively), none of the samples have exceeded the MAL for Pb, whereas for Cd, the liver and kidneys from all three organisms have exceeded the MAL for Cd. According to provisional tolerable weekly intake levels (PTWI) for Pb...

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