Milk of cattle and goat was collected from various localities of Faisalabad, Pakistan. Heavy metal concentration in milk was determined by atomic absorption spectrophotometer. Milk from both of the species was found richly contaminated with cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb). Lead concentration in the milk of goat was significantly higher as compared to cattle milk. Quantitative structure activity relationship (QSAR) models were suggested to predict the residues of unknown heavy metals in the milk of cattle and goat using their known physicochemical properties such as molecular weight (MW), melting point (MP), and boiling point (BP) as well as the milk characteristics such as pH, % fat, and specific gravity (SG) of both of these species. The analysis revealed good correlation coefficients (R2 = 0.759) and (R2 = 0.876) for cattle and goat QSAR models, respectively. This analysis indicates the need to construct species specific QSAR models for residue prediction. The coefficients for SG for the studied metals were higher in both cattle and goat milk. This suggests that SG is a better determinant for heavy metal residue prediction in the milk of these animals. Risk analysis was conducted based upon the determined heavy metal residues and their provisional tolerable daily intakes. The daily intake of Cd, Cr, and Pb was found to be 1.6, 27, and 116 times higher, respectively, in cattle milk and 1.8, 29, 262 times higher respectively, in goat milk. This intake of heavy metal contaminated milk might pose health hazards to humans in this locality.

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BackgroundEnvironmental contamination is a major concern for nosocomial infections in neonatal units. Sources of contamination are multiple and contamination with pathogens occurs during routine medical care. Diverse types of pathogens have been found to cause nosocomial infections. Environmental disinfection and fumigation for their eradication have shown conflicting results.AimThis study was designed to find out the potential sources of infection in our set-up and role of various methods in its eradication.MethodsThis was a cross sectional study and conducted at tertiary care Neonatal unit from March 2007 to October 2012. We obtained samples for culture from air, liquid materials like Oxygen flow metre water and solid materials like equipment, walls and windows of the unit before and after disinfection and fumigation with formalin solution and carbolic acid. Data was entered and analysed in SPSS 16. Chi square test was applied to determine the significance and P value < 0.05 was considered as significant.ResultsTotal 556 cultures were taken from various environmental sources. In the pre fumigation and disinfection stage 227 out of 288 cultures were positive while only 94 isolates were detected from 268 samples after fumigation and disinfection (Figure 1) (P < 0.05). Table 1 shows the culture comparison of different sources of Neonatology unit before and after fumigation and disinfection. Microorganism detected from different sources were Staphylococcus epidermidis (n = 96) followed by Bacillus spp. (n = 67), Klebsiella spp. (n = 59), Staphylococcus aureus (n = 32) and Pseudomonas spp. (n = 29).Abstract G413(P) Figure 1 Cultures results before after fumigation and disinfection (p = 0.02)Abstract G413(P) Table 1Culture comparison of different sources of neonatology unit after fumigationConclusionPathogenic microorganisms were isolated from various sources of neonatal ward and were potential reservoirs for nosocomial infections. Environmental disinfection and fumigation was effective in reducing their burden. However fumigation was unsuccessful in disinfecting the environmental air.

Authors' Contribution KNW conceived the project, collected the samples, planned and performed the research, statistically analyzed the data and composed the research paper. ZM and SH guided, facilitated and supervised the research.