Microplastics abundance in abiotic and biotic components along aquatic food chain in two freshwater ecosystems of Pakistan.

Contaminants of global concern, microplastics (MPs) have been lately reported to be found almost everywhere. Yet there is limited evidence to suggest if these tiny particles can bioaccumulate and biomagnify along the food chain. The current study was conducted to quantify MPs load in two fresh water bodies i.e. River Ravi (Pakistan) and a fish rearing pond fed with ground water to trace MPs along the food chain including biotic and abiotic components. Samples were taken from air, water, sediments, planktons, fish and avian specimen from both water bodies. Higher MPs were found in all samples taken from river Ravi ranging from 3.0 ± 1.58 MPs items in water to 15.20 ± 3.35 MP items in air as compared to 2.8 ± 1.79 MPs in water to 11.20 ± 1.89 air-borne MP items in fish rearing ponds respectively. The mean value of MP items in the GIT of all species was higher (5.05 ± 2.25) as compared to the respiratory tract (1.57 ± 1.3) suggesting ingestion as main mode of exposure. However, this mode of exposure needs to be further investigated along with other exposure routes. Presence of MPs at all trophic levels under investigation indicates some degree of bioaccumulation of these pollutants in the ecosystems.

Molecular sequencing and phylogenetic analysis of bioaerosols in hospital wards with different ventilation conditions.

INTRODUCTION: Bioaerosols are one of major sources of hospital-acquired infections (HAI's) that can pose serious health implications to the patients, health care workers and visitors in the hospitals across the world. METHODOLOGY: In this study, the molecular identification and phylogenetic analysis of bioaerosols collected from Orthopedic Wards (OW) and Orthopedic Emergency Rooms (OER) of six hospitals in Lahore, Pakistan was done to investigate their diversity and genetic relatedness. Moreover, the role of different ventilation practices (i.e., centrally air-conditioned and non-central air-conditioned) in determining bioaerosols load was evaluated by using both culture and non-culture based (Flow cytometry) approaches. RESULTS: The molecular characterization based on 16S rRNA gene and phylogenetic analysis of frequently recovered bacterial isolates showed 97-99% similarity to diverse sources i.e., air, soil and clinical strains isolated from various countries. The centrally air-conditioned hospitals had significantly lower levels of bioaerosols at most of the sites as compared to non- central air-conditioned hospitals. CONCLUSIONS: The molecular characterization and phylogenetic analysis based on 16S rRNA gene sequences can be effective tool in identifying nature and evolution of bioaerosols, and can improve infection control and surveillance in hospitals. The observed levels of bioaerosols suggest hospitals equipped with central air conditioners have considerably more air hygiene compared to non-central air conditioning systems. These findings are imperative for informing policies on planning and implementation of infection control strategies in hospitals in resource limited settings.

An Investigation into the Accumulation of Air Borne Trace Metals in the Lungs of Common Myna Acridotheres tristis and Bank Myna Acridotheres ginginianus Captured from Urban and Semi Urban Areas of Lahore and Pattoki, Pakistan.

With increasing urbanization and industrialization, clean air is becoming a scarce resource. During the present investigation, concentrations of metals (Pb, Ni and Zn) in the atmosphere and their subsequent deposition in the lungs of two common avian species, common myna, Acridotheres tristis (n = 30) and bank myna, A. ginginianus (n = 20), captured from urban areas of Lahore city and semi-urban areas of Pattoki city 80 km away from main city of Lahore were determined. The obtained results were analyzed statistically using Independent sample t test and Pearson's correlation. A comparison of trace metal concentrations in air of both the cities was also carried out. Statistically, significant variations were recorded for Pb (t (7) = - 4.276, p = 0.001) while non-significant differences were observed for both Ni (t (7) = 0.049, p = 0.962) and Zn (t (7) = 1.555, p = 0.146).