Microbial Health Risks of Cryptosporidium parvum and Giardia lamblia in Tropical Coastal Water in Araromi, Nigeria.

Objective: Giardia and Cryptosporidium are enteric protozoa that can cause a variety of gastrointestinal diseases, especially in vulnerable people like children, the elderly, and those with impaired immune systems. In order to ascertain the microbiological quality of the recreational water from Araromi Beach in Ilaje Local Government Area, Ondo State, Nigeria. This risk assessment is of great significance to human health protection against waterborne diseases. The aim of this study was to determine the microbial quality of recreational water from Araromi Beach in Ilaje Local Government Area, Ondo State, Nigeria. Methods: Microscopic examination of Cryptosporidium and Giardia oocysts were done. Results: Results revealed maximum occurrence of Cryptosporidium parvum (20 oocysts/100 mL) of water sample in the month of April and maximum occurrence of Giardia lamblia (300 cysts/100 mL) of water sample in the month of June. Additionally, according to Kolmogorov-Smirnov tests for normalcy Ho =0.05, Giardia lamblia and Cryptosporidium parvum were not regularly distributed in the water samples collected from the beach throughout the study period. The average likelihood of contracting Giardia lamblia and Cryptosporidium parvum infections after consuming 100 mL of beach water was 0.96 and 0.35, respectively. The risks of infection associated with Cryptosporidium parvum was lower than those associated with Giardia lamblia in water from the beach, but were both above the acceptable risk limit of 10-4. Conclusion: The results of this study indicate that Giardia and Cryptosporidium may represent serious health hazards to people who engage in aquatic activities. Adopting a comprehensive strategy that includes regular inspections, enhanced detection techniques, and the prevention of aquatic environment pollution may provide clean and safe recreational water for all, thereby safeguarding the public's health.

Sanitary inspection and microbial health risks associated with enteric bacteria in groundwater sources in Ilara-Mokin and Ibule-Soro, Nigeria.

This study set out to determine the sanitary risk scores and microbial health risks associated with wells and boreholes in Ilara-Mokin and Ibule-Soro, Nigeria. Water samples (n = 96) were collected over a period of five months to determine the levels of enteric bacteria and to perform a Quantitative Microbial Risk Assessment (QMRA) of drinking water quality. Sanitary risk scores revealed `medium' and `low' overall risks for the wells and boreholes, respectively. Three risk factors (faulty fence; small apron; pollution sources) exhibited high significant (p < 0.01) association with the presence of E. coli and thermotolerant coliforms in water samples from the wells. E. coli and Salmonella ranged from 1.82 to 2.28 and 2.15 to 2.63 log10 CFU/100 ml respectively in water from the wells, but were below detection limit in water from the boreholes. Shigella and Campylobacter were detected in all water samples. Estimated risks of infection associated with Shigella (2.1 × 10-2 to 2.3 × 10-1) were higher than those of Campylobacter (6.7 × 10-2 to 1.9 × 10-1) and Salmonella (1.9×10-3 to 5.6×10-3). Adaption of water safety plans may be advantageous in these settings, since intentional ingestion of water from the wells and boreholes may pose potential risks of diarrheal illness to humans.

Environmental impacts of covid-19 pandemic: Release of microplastics, organic contaminants and trace metals from face masks under ambient environmental conditions.

The covid-19 pandemic era was characterized by heavy usage and disposal of medical face masks, now estimated at over 1.24 trillion. Few studies had attempted to demonstrate the release of microplastics from face masks using simulated conditions and application of mechanical forces, far different from the effects experienced by face masks dumped in the open environment, in landfills and dumpsites. In the current study, we monitored the release of microplastics, organic contaminants and toxic metals from medical face masks degraded under normal outdoor environmental conditions, over a period of 60 weeks. We showed that face mask's decomposition proceeded via sunlight (UV) - initiated oxidative degradation, leading to the replacement of methylene (CH2-) and alkyl (CH3-) groups in face mask's polypropylene backbone with hydroxyl and ketonic functional groups. Organic compounds released from decaying face masks into the surrounding soil included alkanes, alkenes, carboxylic acids/diesters and phthalate esters. Mean maximum concentration of phthalates in the soil ranged from 3.14 mg/kg (diethyl phthalate) to 11.68 mg/kg di(2-ethylhexyl) phthalate. Heavy metals, including Cu, Pb, Cd, As, Sn and Fe, were released into the soil, leading to contamination factors of 3.11, 2.84, 2.42, 2.26, 1.80 and 0.99, respectively. Together, the metals gave a pollution load index (PLI) of 2.102, indicating that they constitute moderate pollution of the soil surrounding the heap of face masks. This study provides a realistic insight into the fate and impacts of the enormous amounts of face masks, disposed or abandoned in soil environments during the covid-19 pandemic.

COVID-19 face masks attracted Cellulomonas and Acinetobacter bacteria and provided breeding haven for red cotton bug (Dysdercus suturellus) and house cricket (Acheta domesticus).

This study investigated the possibility of COVID-19 medical face masks to affect bacterial and macrofaunal communities in open soil environment. An estimated 1.24 trillion of face masks have been used and discarded as a result of the COVID-19 pandemic, with a significant part of this ending up in the soil environment, where they degrade gradually over time. Because bacteria and macrofauna are sensitive indicators of changes in soil ecosystem, we investigated possible impacts of face masks on population, distribution, and diversity of these soil species. Effect on soil bacterial community was studied by both culture-based and advanced molecular (metagenomics) approach, while impact on macrofauna was investigated by examining monoliths around heap of masks for soil insects. In both cases, control soil experiments without face masks were also set up and monitored over a period of 48 weeks. The study found that the presence of face masks led to a more diverse bacterial community, although no influence on overall bacterial population was evidenced. More importantly, bacteria belonging to the genera Cellulomonas and Acinetobacter were found prominently around face masks and are believed to be involved in biodegradation of the masks. The bacterial community around the masks was dominated by Proteobacteria (29.7-38.7%), but the diversity of species increased gradually with time. Tiny black ants (Monomorium invidium) were attracted to the face masks to take advantage of water retained by the masks during the period of little rainfall. The heaps of face masks also provided shelter and breeding "haven" for soil insects, notably the red cotton bug (Dysdercus suturellus) and house cricket (Acheta domesticus), thereby impacting positively on the population of insect species in the environment. This study provides insights into the actual impacts of face masks on soil organisms under normal outdoor environmental conditions.

Microbial health risks associated with rotavirus and enteric bacteria in River Ala in Akure, Nigeria.

AIM: This study was carried out to determine the microbial health risks associated with surface water commonly used for bathing, drinking, domestic and irrigational activities in Akure, Nigeria. METHODS AND RESULTS: Water samples were collected from the river from March to June, 2018. The load of enteric bacteria, somatic coliphages and rotavirus in the water samples was determined using culture-based methods and molecular technique. The physicochemical characteristics of the water samples were determined using standard methods. The risks of rotavirus, Salmonella and Shigella infections resulting from ingestion of the water from the river, were estimated using dose-response model. Redundancy analysis revealed that the levels of E. coli and Salmonella were highly associated with salinity and turbidity. The risks of infection associated with rotavirus (3.3 × 10-3 ) were higher than those associated with Salmonella (1.3 × 10-4 ) and Shigella (1.3 × 10-3 ), and were all above the WHO acceptable risk limit (10-4 ). CONCLUSION: Accidental or intentional ingestion of water from the river may pose potential risks of gastrointestinal illness to humans. SIGNIFICANCE AND IMPACT OF STUDY: Quantitative microbial risk assessment is essential in establishing adequate water management practices that must be strictly followed in order to protect human health.

Detection of enteric bacteria in two groundwater sources and associated microbial health risks.

The microbial quality of two groundwater sources (well and borehole) and associated risks were quantitatively assessed. Water samples from the selected borehole and well were collected over a period of 12 weeks (n = 48). The concentrations of Escherichia coli, faecal coliforms, Salmonella, Shigella, Clostridium, Bifidobacterium and Campylobacter were determined using standard microbiological methods, which involve the use of a membrane filter technique. The water samples were filtered through a 0.45 µm membrane filter using vacuum pump pressure and plated on selective agar for the bacteria under test. The number of colonies of the bacterial growth observed after the incubation period was counted and recorded. The physicochemical properties of the water were determined using standard methods. The risk of Salmonella, Shigella, Clostridium and Campylobacter infections resulting from the ingestion of water from the borehole and well was estimated. The results showed that the levels of enteric bacteria in the borehole were higher than those in the well. The mean levels of E. coli in water from the borehole and well were 3.3 and 1.7 log10 cfu/100 ml, respectively, and exhibited a negative relationship with salinity (r = -0.53). The estimated risks of infection associated with the pathogens in water from the borehole and well were greater than the acceptable risk limit of 10-4 and followed this order Clostridium < Salmonella < Campylobacter < Shigella. The findings of this study suggest recent and continuous faecal contamination of the two groundwater sources, thus exposing the residents relying on the water for drinking to potential risks of gastrointestinal infections.