Quantitative Microbial Risk Assessment (QMRA) of Workers Exposure to Bioaerosols at MSW Open Dumpsites.

The bioaerosol exposure data from the study by Akpeimeh, Fletcher, and Evans (2019) was used to compute the risk of infection from the exposure of dumpsite workers to Aspergillus fumigatus and Escherichia coli O157:H7. A stochastic (Markov Chain) model was used to model the transport of the inhaled dose though the human respiratory system and then integrated into the beta-Poisson dose-response model to estimate workers risks of respiratory and gastrointestinal (GI) infection. The infection risk was computed based on workers exposure to E. coli O157:H7 at 10-50% pathogen ingestion rate and pathogen-indicator ratio (P:I) of 1:103 and 1:104 , while exposure to A. fumigatus was based solely on the average initial exposure dose. The results showed that after 11 hours of exposure, workers engaged in scavenging, waste sorting, and site monitoring were at risk of respiratory and GI infection in the magnitude of 10-1 . However, the risk estimates associated with specific areas of the dumpsite showed that, the risk of GI infection at the active area ranged between 3.23 × 10-3 -1.56 × 10-2 and 3.25 × 10-4 -1.62 × 10-3 ; dormant area 2.06 × 10-3 -1.01 × 10-2 and 2.09 × 10-4 -1.04 × 10-3 ; entrance 1.85 × 10-3 -9.09 × 10-3 and 1.87 × 10-4 -9.27 × 10-4 ; boundary 1.82 × 10-3 -8.82 × 10-3 and 2.09 × 10-4 -8.94 × 10-4 for P:I = 1:103 and 1:104 respectively, while the risk of respiratory infection risks were in the magnitude of 10-1 for all four locations. The estimated risk of workers developing respiratory and gastrointestinal infections were high for all activities assessed at the dumpsite.

Pilot-scale biofiltration at a materials recovery facility: The impact on bioaerosol control.

This study investigated the performance of four pilot-scale biofilters for the removal of bioaerosols from waste airstreams in a materials recovery facility (MRF) based in Leeds, UK. A six-stage Andersen sampler was used to measure the concentrations of four groups of bioaerosols (Aspergillus fumigatus, total fungi, total mesophilic bacteria and Gram negative bacteria) in the airstream before and after passing through the biofilters over a period of 11 months. The biofilters achieved average removal efficiency (RE) of 70% (35 to 97%) for A. fumigatus, 71% (35 to 94%) for total fungi, 68% (47 to 86%) for total mesophilic bacteria and 50% (-4 to 85%) for Gram negative bacteria, provided that the inlet concentration was high (103-105 cfu m-3), which is the case for most waste treatment facilities. The performance was highly variable at low inlet concentration with some cases showing an increase in outlet concentrations, suggesting that biofilters had the potential to be net emitters of bioaerosols. The gas phase residence time did not appear to have any statistically significant impact on bioaerosol removal efficiency. Particle size distribution varied between the inlet and outlet air, with the outlet having a greater proportion of smaller sized particles that represent a greater human health risk as they can penetrate deep into the respiratory system where gaseous exchange occurs. However, the outlet concentrations were low and would further be diluted by wind in full scale applications. In conclusion, this study shows that biofilters designed and operated for odour degradation can also achieve significant bioaerosol control in waste gas.

Plasma Fibrinogen Levels of Healthy Non-Pregnant Women in Calabar; South-South Nigeria

In recent years the role of plasma fibrinogen as an independent cardiovascular risk factor has been increasingly recognized. Most of the studies on the relationship between plasma fibrinogen and cardiovascular risk have been in men; with that in women less investigated. Haemostatic and endothelial function in relation to thrombogenesis and CHD may be particularly important in women because women with myocardial infarction and angina chest pain are more often free of angiographically visualized coronary atherosclerosis than are men. This study was to establish the plasma fibrinogen level of adult women seen in the Outpatient Clinic. One hundred non-pregnant women attending the University of Calabar Teaching Hospital General Outpatient Clinic (GOPC) aged between 18-90 years who met the inclusion criteria and gave informed consent were recruited into the study. Each subject had 4.5mls of venous blood sample collected by vene-puncture using a plastic syringe. This was transferred into a tube containing 0.5ml of trisodium citrate (10:1 dilution); this was centrifuged immediately and plasma analysed for fibrinogen concentration by the modified Clauss technique. Comparison between pre-menopausal; peri-menopausal and post-menopausal groups was done by one-way analysis of variance (ANOVA) followed by student's t-test. A p value of less than 0.05 was considered as significant. The fibrinogen concentration (mg/dl) were 257+44; 315+40 and 579+99 for pre-menopausal; peri-menopausal and post-menopausal women respectively (p0.05). ANOVA showed a Critical F-ratio 3.07; calculated df ratio was 220 (p0.05). Collorary to the ANOVA; student t-test of 1.7 (p0.05) between pre-menopausal and peri-menopausal women; pre-menopausal and post-menopausal women 6.2 (p0.05); and peri-menopausal and post-menopausal women 3.5 (0.05). The critical range for student t-test was 12.7; while calculated t ratio was less. The foregoing findings raise a serious concern for Hormone Replacement Therapy (HRT) using estrogens in women with severe symptoms of menopausal syndrome. Although the fattening room practice termed `Nkuho' or `Mbobo' among the Calabar women is on the decline it exposes women of reproductive age to increased cardiovascular risk. It is thus necessary that Primary Care Physicians begin to include plasma fibrinogen estimations as part of cardiovascular risk profiling as a health promotion strategy in all women of reproductive age

Exposure of petrol station attendants and auto mechanics to premium motor sprit fumes in Calabar, Nigeria.

A population-based-cross-sectional survey was carried out to investigate the potential risk of exposure to premium motor spirit (PMS) fumes in Calabar, Nigeria, among Automobile Mechanics (AM), Petrol Station Attendants (PSA) and the general population. Structured questionnaire was administered on the randomly chosen subjects to elicit information on their exposure to PMS. Duration of exposure was taken as the length of work in their various occupations. Venous blood was taken for methaemoglobin (MetHb) and packed cells volume (PCV). Mean MetHb value was higher in AM (7.3%) and PSA (5.8%) than in the subjects from the general population (2.7%). PCV was lower in PSA (30.8%), than AM (33.3%) and the subjects from the general population (40.8%). MetHb level was directly proportional, and PCV inversely related, to the duration of exposure. The study suggested increased exposure to petrol fumes among AM, PSA, and MetHb as a useful biomarker in determining the level of exposure to benzene in petrol vapour.

HIV/AIDS Awareness among Traders in Port-Harcourt; Rivers State; Nigeria

A pilot study was carried out involving 193 market traders randomly selected from the three markets in the Port Harcourt metropolis; of Rivers State; Nigeria. A questionnaire was administered to investigate the HIV/AIDS awareness of these traders. Fifty (50) percent of the respondents were in the age range of 21 to 30 years; 69were single and 95were Christians. The results indicate that the traders were knowledgeable about HIV/AIDS. However; there were some misconceptions. Though highly sexually active; only 18considered themselves at risk of contracting or having contracted the virus. The news media scored highest as a source of HIV/AIDS information. A high percentage (56) of the respondents claimed that their sexual behaviours have not been altered as a result of the HIV/AIDS awareness but 73will now advise/ use a condom. It appears that these traders will now exercise caution in negotiating new sexual relationships. It is recommended that awareness be scaled up; considering that majority of these traders are not literate; are making meager incomes and therefore might be tempted to consider sex; as a means of augmenting these meager incomes

Worm infestation and anaemia among pre-school children of peasant farmers in Calabar, Nigeria.

BACKGROUND: Worm infection and anaemia are common childhood conditions in Nigeria. We assessed the status of helminthiasis and associated anaemia among pre school children of peasant farmers aged 1-5 years living in a rubber plantation near Calabar, Nigeria. DESIGN: Cross sectional. METHOD: Three hundred and fifty children were selected by multi-stage cluster sampling technique. Freshly passed stool was examined using Kato-Katz method while anaemia was estimated using haematocrit technique. RESULT: Of the 350 children, 174 (49.7%) had intestinal helminths: Ascaris lumbricoides 64.4%, hookworms 10.9% and Trichuris trichuria 1.1%. There were 41(23.6%) children with polyparasitism, 33 of them were due to Ascaris lumbricoides and hookworms. The worm load was generally light in intensity with egg per gram of stool ranging from 24-60,960. Males (28.9%) were infected more than females (20.8%). The frequency of infection increases with age. The prevalence of anaemia among the entire study population and in those infected with worms was 56.6% and 56.9% respectively. With polyparasitism there was a relative increase in the frequency of anaemia females > males. CONCLUSION: Worm infections and anaemia are common in our children. A comprehensive control strategy involving good sanitation, sinking of bore hole for clean water supply and regular deworming exercises are recommended.

Significance of platelet activation in sickle cell anaemia.

BACKGROUND: There is increasing evidence suggesting the contribution of platelets in the vaso-occlusive phenomena found in sickle cell anaemia. This study is aimed at using simple, inexpensive parameters to determine the role of platelets in the steady state and vaso-occlusive crisis state of Nigerian sickle cell anaemia patients. METHODS: The circulating platelet aggregate (CPA) ratio, platelet factor-3 availability (PF-3) and platelet counts of 60 adult Nigerian sickle cell anaemia patients were studied. RESULTS: The CPA ratio in the sickle cell anaemia (SCA) patients in steady state (SS) was 0.93 +/- 0.05, 0.89 +/- 0.04 during vaso-occlusive crisis (VOC) and 0.98 +/- 0.02 in the control group (C). The values in the vaso-occlusive crisis and in steady state were significantly lower than in the control group (P < 0.05). PF3 availability in steady state and vaso-occlusive crisis were 29.7 +/- 4.0 secs and 28.4 +/- secs respectively. The times are significantly shorter when compared with the control group with a time of 36.2 +/- 4.3 secs (P < 0.05). There was however no significant difference between the two sickle cell groups. Platelet count was significantly raised in the steady state patients 224.3 +/- 46.3 x 10(9)/L when compared with controls of 196.6 +/- 39.3 x 10(9)/L (P < 0.05). There was a significant fall during VOC to 140.6 +/- 36.3 x 10(9)/L (P < 0.05). The difference between the two sickle cell groups is significant (P < 0.05). CONCLUSION: This study indicates varying degrees of partial activation of platelets in vivo in the steady state and vaso-occlusive crisis state of sickle cell anaemia. It support's a contribution of platelet to the vascular occlusion that underlies much of the morbidity in the disease.

Glycaemic control in type 2 diabetics and the mean corpuscular fragility.

BACKGROUND: The osmotic effects of hyperglycaemia and glycosylation of haemoglobin and erythrocyte membrane proteins may play important role in the deformability of RBC in the diabetic state. These effects may be exaggerated in poorly controlled diabetes. The study aimed to determine the fasting blood sugar levels (FBS), glycated haemoglobin (HbA1c) and osmotic fragility of red cells (MCF) in diabetics and non-diabetics. METHODS: Fasting blood sugar, glycated haemoglobin and red cell osmotic fragility were determined in seventy-two diabetic subjects aged between 35-70 years and thirty age matched non-diabetic subjects in Calabar, Nigeria using colorimetric methods. RESULTS: The FBS, HbA1c and MCF were significantly (p < 0.01) higher in diabetics than in non-diabetic subjects. The MCF of diabetics with FBS levels > 7.00mmol/l was significantly higher than those with FBS levels < 7.00mmol/l. No significant difference was observed in the MCF between diabetics with poor glycaemic control (HbA1c > 8.0%) and those with good glycaemic control (HbA1c < 8.0%). The MCF of patients who has been suffering from diabetes for less than five years were significantly (p < 0.05) higher than those who have had the disease for more than five years. A positive correlation (p < 0.003, r = 0.340) was observed between the FBS and HbA1c in diabetic subjects. No significant association was seen between the MCF and HbA1c of diabetic subjects of the study. CONCLUSION: Hyperglycaemia alters the membrane properties of the red cells leading to increase osmotic fragility of the red cells.

The effect of nocotiana tabacum (snuff) on blood pressure and pulse rate of Nigerians.

Nutritional and environmental factors are now known to affect the blood pressure and pulse rate of man. The present study investigated the effect of nicotiana tabacum on these parameters. Thirty-three male Nigerians (20-68 years) living in Calabar, Nigeria were used for this study. The subjects were treated at three different periods with snuff containing varied concentrations of Natron (0.5g and 10g/100g of snuff) and their systolic and diastolic pressures as well as pulse rate were measured at intervals of 30 minutes up to a maximum of 90 minutes. Each subject served as his own control. There were significant and time-dependent increases in the parameters measured. In addition, the increases were more marked in the absence of Natron than in its presence.