Godson Ana

Lead poisoning associated with malaria in children of urban areas of Nigeria

The principal objectives of this study are to (a) investigate the prevalence of elevated blood lead levels (EBLLs) in children of three major cities of Nigeria with different levels of industrial pollution; (b) identify the environmental, social and behavioral risk factors for the EBLLs in the children; and (c) explore the association between malaria (endemic in the study areas) and EBLLs in the pediatric population. The study involved 653 children aged 2-9 years (average, 3.7 years). The mean blood lead level (BLL) for the children was 8.9+/-4.8microg/dL, the median value was 7.8microg/dL, and the range was 1-52microg/dL. About 25% of the children had BLL greater than 10microg/dL. There were important differences in BLLs across the three cities, with the average value in Ibadan (9.9+/-5.2microg/dL) and Nnewi (8.3+/-3.5microg/dL) being higher than that in Port Harcourt (4.7+/-2.2micro/dL). Significant positive associations were found between BLL and a childs town of residence (p<0.001), age of the child (p=0.004), length of time the child played outside (p<0.001), presence of pets in a childs home (p=0.023), but negatively with educational level of caregiver (p<0.001). This study is one of the first to find a significant negative association between BLL and malaria in a pediatric population, and this association remained significant after controlling for confounding diseases and symptoms. The shared environmental and socio-demographic risks factors for lead exposure and Plasmodium (most common malaria parasites) infection in urban areas of Nigeria are discussed along with possible ways that lead exposure may influence the host response to infection with malarial parasites.

Polycyclic aromatic hydrocarbons and their quinones modulate the metabolic profile and induce DNA damage in human alveolar and bronchiolar cells.

The release of particulate pollutants into the air through burning of coal, crude oil, diesel, coal tar, etc. raises concerns of potential health hazards to the exposed human population. Polycyclic aromatic hydrocarbons (PAHs) are major toxic constituents of particulate matter (PM), which upon ingestion get metabolized to even more toxic metabolites such as quinones. The PAHs levels were assessed in both respirable particulate matter (RSPM, <10μM size) and suspended particulate matter (SPM, >10μM size) of urban ambient air (UAA) and that of major contributors viz. diesel exhaust particles (DEPs) and coal tar combustions emissions (CTCE). Seven US Environmental Protection Agency (USEPA) prioritized PAHs in RSPM and 10 in SPM were detected in UAA. Ten and 15 prioritized PAHs, respectively, were also detected in diesel exhaust particles (DEP) and coal tar combustion emission (CTCE) evidencing their release in the air. These PM associated PAHs for UAA, DEP and CTCE showed significant increase (p<0.05) in mutagenicity and mammalian genotoxicity in the order CTCE>DEP>UAA. Human lung alveolar (A549) and bronchiolar (BEAS-2B) cells when treated with PAH-metabolites viz. 1,4-benzoquinone (1,4-BQ), hydroquinone (HQ), 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ) and 9,10-phenanthroquinone (9,10-PQ) showed metabolic modulation in these cell lines with significant depletion of principal cellular metabolites viz. NADP, uracil, asparagines, glutamine, and histidine and accumulation of di-methyl amine and beta-hydroxybutyrate, identified using (1)H NMR spectroscopy. These results suggest that PAH-quinones induce genotoxic effects by modulating the metabolic machinery inside the cells by a combined effect of oxidative stress and energy depletion. Our data for metabolic profiling of human lung cells could also help in understanding the mechanism of toxicity of other xenobiotics.

Relationship between Household Air Pollution from Biomass Smoke Exposure, and Pulmonary Dysfunction, Oxidant-Antioxidant Imbalance and Systemic Inflammation in Rural Women and Children in Nigeria

Background: Exposure to particulate matter from burning biomass fuels is believed to affect oxidant-antioxidant balance and to induce oxidative stress. Methods: Fifty-nine mother-child pairs from 59 households that used firewood exclusively for cooking in three rural communities in southwest Nigeria underwent blood test for albumin, pre-albumin, retinol-binding protein (RBP), superoxide dismutase (SOD), vitamins C, vitamin E, malondialdehyde (MDA) and C-reactive protein (CRP). Spirometry was performed and indoor levels of PM2.5 were determined. Results: Mean age (± SD; years) of mothers and children was 43.0±11.7 and 13.6±3.2, respectively. The median indoor PM2.5 level was 1575.1 µg/m3 (IQR 943.6–2847.0, p<0.001), which is substantially higher than the World Health Organization (WHO) standard of 25 µg/m3. The mean levels of pre-albumin (0.21±0.14 g/dL) and RBP (0.03±0.03 g/dL) in women were significantly lower than their respective normal ranges (1-3 g/dL and 0.2-0.6 g/dL, respectively, p<0.05). Similarly, the mean levels of pre-albumin (0.19±0.13 g/dL) and RBP (0.01±0.01 g/dL) in children were significantly lower than the respective normal ranges (1-3 g/dL and 0.2-0.6 g/dL, respectively, p<0.05). Mean serum concentrations of MDA in children (5.44±1.88 µmol/L) was positively correlated to serum concentrations of CRP (r=0.3, p=0.04) and negatively correlated to lung function (FEV1/FVC) in both mothers and children (both r=-0.3, p<0.05). Also, regression analysis indicates that CRP and SOD are associated with lung function impairment in mothers (-2.55±1.08, p<0.05) and children (-5.96±3.05, p=0.05) respectively. Conclusion: Exposure to HAP from biomass fuel is associated with pulmonary dysfunction, reduced antioxidant defense and inflammation of the airways. Further studies are needed to better define causal relationships and the mechanisms involved.

Assessment of noise and associated health impacts at selected secondary schools in Ibadan, Nigeria.

Background. Most schools in Ibadan, Nigeria, are located near major roads (mobile line sources). We conducted an initial assessment of noise levels and adverse noise-related health and learning effects. Methods. For this descriptive, cross-sectional study, four schools were selected randomly from eight participating in overall project. We administered 200 questionnaires, 50 per school, assessing health and learning-related outcomes. Noise levels (A-weighted decibels, dBA) were measured with calibrated sound level meters. Traffic density was assessed for school with the highest measured dBA. Observational checklists assessed noise control parameters and building physical attributes. Results. Short-term, cross-sectional school-day noise levels ranged 68.3–84.7 dBA. Over 60% of respondents reported that vehicular traffic was major source of noise, and over 70% complained being disturbed by noise. Three schools reported tiredness, and one school lack of concentration, as the most prevalent noise-related health problems. Conclusion. Secondary school occupants in Ibadan, Nigeria were potentially affected by exposure to noise from mobile line sources.

Polycyclic aromatic hydrocarbon burden in ambient air in selected Niger Delta communities in Nigeria.

The Niger Delta area in Nigeria has major oil producing and refining centers that characterized enormous industrial activities, especially in the petroleum sector. These industrial processes release different kinds of atmospheric pollutants, of which there is paucity of information on their levels and health implications. The objective of this study was to determine the ambient levels of polycyclic aromatic hydrocarbons (PAHs) in communities of a local government area (Eleme) where oil wells, petrochemical installations, a refinery, and a fertilizer complex are located. Respirable particulate matter (PM) in air were collected using Anderson high-volume sampler with PM with aerodynamic diameter ≥10 μm (PM10) inlet for collecting filterable, particle-bound PAHs according to standard methods. PAHs were analyzed following standard methods for the 16 World Health Organization (WHO) prioritized components. The results were compared against the levels in another local government area (Ahoada East) with low industrial presence. The average total PAH concentration in Eleme of 9.2 µg/m3 was among the highest in the world; by contrast, the average concentration in Ahoada East was only 0.17 ng/m3. The most prominent PAHs at Eleme were those known to be carcinogenic and included benzo(a)pyrene (1.6 × 104 ng/m3 at bubu), benzo(k)fluoranthene (2.4 × 104 ng/m3 at Akpajo where a petrochemical is located), pyrene (3.1 × 103 ng/m3 at Ogale), and indeno(1,2,3-cd)pyrene (9.1 × 103 ng/m3 at Akpajo). Data from this study emphasize the need for a comprehensive source apportionment study and an assessment of the health effects of oil production on local communities of Nigeria where no such information currently exists. Implications: This investigation reveals that communities adjoining industrial locations in Nigerias Delta area are more exposed to higher concentrations of pollutants. This predisposes affected communities to environmentally induced health problems. The scenario requires a review of policy that would compel industrial facilities in the area to improve their pollution control regimes. This should be supported by stringent environmental monitoring by regulatory authorities. Also there is the need for in-depth epidemiological and toxicological studies in order to establish causality between the environmental exposure factors and emerging health problems. The outcome of such studies would be critical for instituting intervention programs in the area.

Identification and Initial Characterization of Prominent Air Pollution Sources and Respiratory Health at Secondary Schools in Ibadan, Nigeria

Objective. Research on air quality in and around schools, and the associated vulnerability of school-age children, is limited in less developed countries (LDCs), particularly Africa. The main objective of this study was to conduct an initial assessment of sources of air pollution in and around schools as a surrogate for air quality and report adverse health effects among students at selected secondary schools in urban Ibadan, Nigeria. Methods. The study was a descriptive cross-sectional survey involving eight secondary schools selected purposively, defined with eight acronyms (listed alphabetically): ABHS, AGS, BOHS, CDSS, IGS, LC, MGS, and OAHS. We used pre-tested, self-administered questionnaires, observational checklists to assess certain environmental health indicators, and interviews. The questionnaire was divided into five sections including environmental and health conditions. A total of 400 students from senior secondary classes, 50 from each school, were selected through stratified random sampling. Results. The schools location, especially if close to high traffic roadways, contributed to reported perceived poor air quality of school environments. The majority of students believed air pollution sources in the school environment were mainly refuse burning and car emissions from nearby roadways. Cough and asthma were the most frequently reported adverse health outcomes. The highest prevalence of reported recent asthma episodes (symptoms) were recorded at BOHS (84%) and at CDSS (62%); furthermore, at ABHS it was nearly 1-in-2 students and at OAHS about 1-in-5 students. BOHS and OAHS each reported over 10% for prevalence of bronchitis. Conclusions. Proximity of study schools to certain sources and activities such as refuse burning and major roadways seemed to present substantial risk factors for reported respiratory morbidity among secondary students in urban Ibadan, Nigeria. Future research should quantify source emissions and exposure and further characterize frequency and severity of respiratory symptoms, among other parameters, at schools in Nigeria and other sprawling urban areas of Africa.

Outdoor respirable particulate matter and the lung function status of residents of selected communities in Ibadan, Nigeria.

Background: Ambient air pollution remains a major public health hazard in urban communities. In Nigeria, air quality management especially in the urban centres, is fraught with enormous challenges including limited data. We assessed the outdoor respirable particulate matter (PM10) concentration and the pulmonary function status of residents in four selected communities in Ibadan. Methods: A cross-sectional study design was employed. Four locations – Ojoo Park (OP = high traffic area), Bodija Market (BM = commercial area), Oluyole Estate (OE = industrial area) and the University of Ibadan (UI = academic community – reference) – were selected based on varying intensities of urban activity. PM10 levels were recorded in the morning and afternoon for 12 weeks between January and March 2008. Lung function status (FEV1) of 140 randomly selected participants was measured. Daily mean of PM10 levels were compared with WHO guideline limits. Data analysis was done using descriptive, χ2, ANOVA and Spearman-rank correlation tests at 5% level of significance. Results: For all sites, PM10 concentration was generally higher in the afternoon. The highest daily mean PM10 concentration was recorded at BM, followed by OP, OE and UI. These values when compared with WHO guideline limits showed: BM eightfold > OP sevenfold > OE sixfold > UI fivefold (p < .05). Weekly mean PM10 levels and mean FEV1(obs) gave the following order: UI > OE > OP > BM. There was a significant negative correlation between PM10 burden and FEV1(obs) across the study locations (r =-0.371, p < .05). Conclusion: Most of the locations with higher particulate burden were observed to have declining lung function status. A longitudinal study to establish more robust associations is advocated.

Spatial–temporal variations in carbon dioxide levels in Ibadan, Nigeria

Growing evidence suggests how global background levels of atmospheric carbon dioxide (CO2) are increasing and this impacts environmental quality and human and ecological health. Data from less developed countries are sparse. We determined spatial and temporal variations in concentrations of CO2 in selected locations in Ibadan, Nigeria with identifiable prominent outdoor sources. Activity driven areas in north and south-west areas were identified and marked with a global positioning system. Waste management practices and activities generating CO2 were documented and described using a technician observation checklist. CO2 levels were measured using a portable TELAIRE 7001 attached to HOBO U12 data loggers across seasons. Mean CO2 levels were compared over seasons, i.e. rainy season months and the dry season months. While CO2 levels recorded outdoors in study areas were comparable to available international data, routine monitoring is recommended to further characterize concurrent pollutants in fossil fuel combustion emissions with known deleterious health effects.

Indoor airborne microbial burden and risk of acute respiratory infections among children under five in Ibadan, Nigeria

Acute respiratory infection is the fourth major cause of morbidity and mortality among under-five children globally. However, the profile of microbial burden that could contribute to these infections among under-five children in the indoor environments has not been extensively studied particularly in developing countries like Nigeria. This study was designed to determine the burden of airborne microbes in indoor environment that predispose under-five children to acute respiratory infections. A prospective case–control design was employed for this study. Two hundred and twenty under-five children each with acute respiratory infection (cases) and without acute respiratory infection (controls) were selected from children visiting Oni-memorial Children Hospital and University College Hospital, Ibadan. A follow-up of 66 consented cases and controls each was carried out to assess the burden of indoor airborne microbes using a non-volumetric method, and the total counts per cubic metre were compared with the American Industrial Hygiene Association guideline. Data were analysed using descriptive statistics, t-test and Spearman’s rank correlation. Mean indoor total bacterial count for cases (9.6 × 102 cfu/m3) was significantly higher than the permissible limit recommended by the American Industrial Hygiene Association (≤500 cfu/m3) as compared to controls (3.5 × 102 cfu/m3) (p < 0.05). Educating mothers of under-five children on improved ventilation, good housing and indoor sanitary practices to reduce indoor microbial load is therefore advocated.

Acute, Repeated Exposure to Mobile Phone Noise and Audiometric Status of Young Adult Users in a University Community

Background. Exposure to noise from mobile devices is suspected to affect hearing. Data are limited, particularly in less developed countries. We assessed noise levels from mobile phones and user audiometric status at University of Ibadan, Nigeria, in an initial cross-sectional study. Methods. Fifty-eight staff and 45 young adult students owning mobile phones were selected. A pretested questionnaire assessed demographics, phone attributes, and predominant ear used for making and receiving calls. Noise was measured in A-weighted decibels. Pure tone audiometry was conducted at varying frequencies. Statistics computed included Chi-square and t-tests. Results. Certain phone brands used by students were commonly reported. More utilized right ears to make or receive calls. Mean reported mobile phone use duration by students was years, lower than among staff, years (). There were differences in use of head phones (22.2%, 12.1%) and speakers (51.1%, 15.5%) by students and staff, respectively (). Mean measured noise levels of phones when ringing, per user settings, were high  dBA (students) and  dBA (staff). Audiometry suggested 22.2% students and 28.0% staff had some evidence of hearing impairment. Conclusions. Mobile phones noise levels were high, but exposures though frequent were of short duration. Larger, longitudinal studies are needed on phone use and hearing impairment.