Publications


2017

Were, FH.  2017.  Take the Lead on Lead. UN Environment; OurPlanet. :44-45.Website

2016

Were, FH.  2016.  Intensified Campaigns to End Use of Lead-Based Paints. The Architect, the Official Magazine of the the Architects Chapter,AAK. (10):28-30.Website
Maureene Auma Ondayo, Gelas Muse Simiyu, Phillip Okoth Raburu, Were FH.  2016.  Child Exposure to Lead in the Vicinities of Informal Used Lead-Acid Battery Recycling Operations in Nairobi Slums, Kenya. Journal of Health and Pollution. 6(12):15-25. Abstractwebsite to access full text

Background. Child exposure to lead from informal used lead-acid battery (ULAB) recycling operations is a serious environmental health problem, particularly in developing countries.

Objectives. We investigated child exposure to lead in the vicinities of ULAB recycling operations in the Dandora, Kariobangi and Mukuru slums in Nairobi between January and August 2015.

Methods. Top soil (n = 232) and floor dust (n = 322) samples were collected from dwelling units (n = 120) and preparatory schools (n = 44) and analyzed using an inductively coupled plasma-optical emission spectrometer at the Mines and Geological Department Laboratory in the Ministry of Mining, Nairobi. From the obtained lead levels in soil and house dust, child blood lead levels were subsequently predicted using the Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK), Windows version.

Results. Lead loadings in all the floor dust samples from the Dandora, Kariobangi and Mukuru slums exceeded the United States Environmental Protection Agency (USEPA) guidance value for lead on floors with a range of 65.2 – 58,194 μg/ft2. Control floor dust samples recorded lower lead loadings compared to the Dandora, Kariobangi and Mukuru slums. Lead concentration in 70.7% of the soil samples collected from waste dumps, industrial sites, residential areas, playgrounds and preparatory schools in Dandora, Kariobangi and Mukuru exceeded the respective USEPA guidance values for lead in soils. Lead concentration in 100% of control soil samples were below the respective USEPA limits. The IEUBK model predicted that nearly 99.9% of children ≤ 7 years old living near informal ULAB recycling operations in Dandora, Kariobangi and Mukuru were at risk of being lead poisoned, with predicted blood lead levels (BLL) above the Centers for Disease Control (CDC) reference value for blood lead. A total of 99.9% of exposed children living in the Mukuru slums are likely to have BLL above 34 μg/dL.

Conclusions. There is a need for coordinated efforts to decrease lead emissions from informal battery recycling in Nairobi slums and to remediate existing soils, particularly around battery workplaces and dumpsites. The BLL of local children should be clinically tested and appropriate intervention measures taken.

Keywords: soil, house dust, predicted child blood lead, used lead-acid battery recycling, Nairobi slums, IEUBK

2014

Faridah H Were, Moturi CM, Wafula GA.  2014.  Chromium Exposure and Related Health Effects among Tannery Workers in Kenya. Journal of Health and Pollution. 4(7):25-35. Abstract

Background. There is increasing concern over the health effects of chromium (Cr) exposure stemming from various activities in tanneries in Kenya. Chromium is a toxic metal in its hexavalent form, and is widely used in the tanning process. Objectives. A detailed exposure assessment of Cr and related health effects among tannery workers in Kenya was performed. Methods. Spot urine and 8-hour full-shift personal breathing zone air samples of the workers (N = 40) and control group (N = 40) were collected and subsequently analyzed for total Cr using atomic absorption spectrophotometry. The medical history, respiratory, and dermatological condition of each of the selected workers was determined. Lung function was further investigated using a spirometer. Results. Tannery workers in various production lines had significantly (P < 0.05) higher mean airborne Cr levels (± standard deviation [SD] of 63.0±11.6 µg/m3) compared to those in the control group (1.39±0.64 µg/m3), and general workers had significantly (P < 0.05) higher mean concentrations of Cr (66.8±13.1 µg/m3) than those in other lines of production. A significant positive association (R2 = 0.76, P < 0.001) was also observed between urinary and breathing zone air Cr levels. Mean urinary Cr level exceeded the American Conference of Governmental Industrial Hygienists biological exposure index for Cr of 30 µg/g creatinine, and 78% of Cr levels of the general workers exceeded this limit. Tannery workers showed a significantly (P < 0.05) higher prevalence of respiratory and dermatological symptoms (30% and 20%, respectively) compared to the control group (10% and 7.5%, respectively). It was further established that production workers had significantly reduced ventilatory function, with 17% experiencing pulmonary obstruction, 13% pulmonary restriction, and 7.5% both manifestations compared to 5% for each of the listed corresponding manifestations in the control group. Conclusions. Our study revealed inadequate engineering controls, work practices and personal hygiene, together with improper management of tannery wastes that has led to considerable exposures to Cr and related health effects among workers.

Key Words. Kenya; developing country; chromium; tannery workers; adverse health effects; respiratory diseases; dermatological condition

Faridah H Were, M Charles Moturi, P Gottesfeld, Wafula GA, Kamau GN, Shiundu PM.  2014.  Lead exposure and blood pressure among workers in diverse industrial plants in Kenya. Journal of occupational and environmental hygiene. 11(11):706-715. AbstractWebsite

The study evaluated airborne exposures and blood lead (BPb) levels in 233 production workers at six diverse industrial plants in Kenya. Blood and personal breathing zone air samples were collected and analyzed for lead (Pb) using atomic absorption spectroscopy. Blood pressure (BP) levels were measured using a standard mercury sphygmomanometer. The results indicated mean airborne Pb levels ± standard deviation (SD) as follows: 183.2 ± 53.6 μg/m3 in battery recycling, 133.5 ± 39.6 μg/m3 in battery manufacturing, 126.2 ± 39.9 μg/m3 in scrap metal welding, 76.3 ± 33.2 μg/m3 in paint manufacturing, 27.3 ± 12.1 μg/m3 in a leather manufacturing, and 5.5 ± 3.6 μg/m3 in a pharmaceutical plant. The mean airborne Pb levels exceeded the U.S. Occupational Safety and Health Administration (OSHA) 8-hr time-weighted average (TWA) permissible exposure limit (PEL) for Pb of 50 μg/m3 in the battery manufacturing, battery recycling, welding, and paint manufacturing plants. Similarly, mean BPb concentrations exceeded the American Conference of Governmental Industrial Hygienists (ACGIH®) biological exposure index (BEI) for Pb of 30 μg/dl. A significant positive association was observed between BPb and breathing zone air Pb (R2 = 0.73, P < 0.001). Approximately 30% of the production workers (N = 233) were in the hypertensive range with an average systolic and diastolic blood pressure (BP) of 134.7 ± 12.7 mmHg and 86.4 ± 8.9 mmHg, respectively. In the multivariate regression analysis, age, duration of work, airborne Pb and BPb levels were significantly associated (P < 0.05) with a change in BP. We recommend improved engineering controls, work practices, and personal hygiene to reduce Pb exposures. In addition, workers should undergo comprehensive medical surveillance to include BPb and BP testing, and airborne Pb assessments in all industries with significant lead exposures.

2013

Were, FH.  2013.  Assessment of Levels of Selected Heavy Metals among Industrial Workers and Related Occupational Health Effects in the City of Nairobi and Athi River Township in Kenya. (G.N. Kamau, Shiundu, PM, Eds.)., Nairobi: University of Nairobi Abstract

The study assessed the concentrations of heavy metals among factory workers (N = 282) and their related adverse health effects in Nairobi and Athi River Township in Kenya. Sets of whole blood, spot urine, scalp hair and personal breathing zone air samples were collected from these workers in various sections of 6 different plants, and analysed for cadmium (Cd), lead (Pb), nickel (Ni) and chromium (Cr) levels using atomic absorption spectrophotometery. This method of analysis was validated using certified reference whole blood samples, BCR®-635 and BCR®-636. The results indicated mean airborne Pb levels ± standard deviation (SD) in production sections as follows: 183.2 ± 53.6 ug/rrr' in battery recycling, 133.5 ± 39.6 ug/m' in battery manufacturing, 126.2 ± 39.9 ug/rrr' in steel and scrap welding, 76.3 ± 33.2 ug/nr' in paint manufacturing, 27.3 ± 12.1 ug/rn" in leather and tannery, and 5.5 ± 3.6 !!g/m3 in the pharmaceutical plant. The average airborne Pb levels in production sections were significantly high (P < 0.05) when t·.... .• compared to those in their respective office areas, which was: 23.9 ± 6.9 ug/rrr', 18.8 ± 1.6 ug/m", 23.5 ± 5.8 ug/m:', 13.8 ± 3.0 ug/rn", 8.0 ± 2.7 ug/m" and 2.1 ± 0.2 ug/nr'. In all cases, the average airborne Pb levels in production areas markedly exceeded the U.S. Occupational Safety Health Administrations' Permissible Exposure Limit of 50 ug/rrr' ~ over an 8-hour Time-Weighted Average except for leather and tannery, and pharmaceutical plant. Blood lead (BPb) levels of all employees correlated positively (r = 0.86) with airborne Pb. All the determined mean BPb values in production workers exceeded 30 ug/dl, proposed by of the American Conference of Governmental for Industrial Hygienists (ACGIH) biological exposure indices (BEls), except for employees in leather and tannery, and pharmaceutical plant. Similarly, levels of Cd, Ni and Cr in the ambient air correlated positively (r = 0.99 Cd, 0.89 Ni and 0.84 Cr, N = 282) with those in the urinary samples. The production areas of steel and scrap welding plant had the highest mean levels of 0.13 ± 0.05 ug/rrr' Cd and 10-:-3±4.3 ug/rrr' Ni in the breathing zone air compared to those in the other plants. In this* facility, 50% (20 of 40) and 27.5% (11 of 40) of employees had urinary Ni and Cd levels that exceeded the ACGIH BEls. The average airborne Cr levels of 23.4 ± 11.6 ug/rrr' were highest in production areas of leather and tannery industry, where urinary mean Cr levels of 35.2 ± 12.1 ug/g exceeded the BEIs. Nearly 71% (22 of 31) and 27.5% (11 of 40) of leather tanners and steel and v scrap welders, respectively had urinary Cr levels that exceeded this limit. A positive correlation of r = 0.55 Cr; 0.61 Pb; 0.58 Cd and 0.30 Ni was also observed in the levels between these metals in the ambient air and hair samples. The relationship between levels of heavy metals in the hair and other biomarkers of exposure further indicated correlation coefficient values (r) of 0.57 for urinary-Cr; 0.51, urinary-Cd; 0.21, urinary- Ni; 0.59, blood-Pb; and 0.42 for blood-Cd. The results also established that a high proportion of steel and scrap welders (47.3%, N 19), battery recyclers (39%, N = 16) and battery manufacturers (37.5%, N = 15) had hypertensive range of blood pressure with high incidences of cardiovascular diseases and related symptoms, which were associated with significantly high levels of Pb and Cd. Almost 10.7% of production workers (N = 233) were anaemic, which was associated with elevated levels of BPb. Leather tanners (48.3%, N = 15) and steel and scrap welders (47.5%, N = 19) had high prevalence of respiratory illnesses that were marked by severely reduced forced' vital capacity (FVC) .' . and forced expiratory volume of air in thi -(l.i;t second (FEV i). These were indication of airway obstructions. It was further observed that leather tanners (41.9%, N = 13) and steel and scrap welders (40.0%, N = 13) had high occurrences of dermatological conditions that manifested in the form of rashes and itching and which were associated with elevated airborne levels of Cr and Ni.

Faridah H Were, M CM, Wafula GA.  2013.  Respiratory Diseases Due to Occupational Exposure to Nickel and Chromium among Factory Workers in Kenya. Journal of Community Medicine & Health Education. 3(7):1-7. AbstractWebsite

Inhalation of airborne nickel (Ni) and chromium (Cr) in workplaces causes a variety of respiratory ailments which
adversely affects the productivity of employees. A study was therefore conducted on production workers (N=233) from
six different types industrial plants, to investigate the influence of Ni and Cr exposure on their respiratory systems.
Breathing zone air and urinary samples were collected, and analyzed for total Ni and Cr using atomic absorption
spectroscopy. The medical history of the workers was obtained using questionnaires. Their lung functions were further
examined using a spirometer. Mean (± standard deviation) breathing zone air of 23.4 ± 11.6 μg/m3 Cr and 10.3 ± 4.3 μg/
m3 Ni was highest among the tanners and welders, respectively. The mean level of 35.2 ± 12.1 Cr and 28.4 ± 7.8 Ni in
μg/g creatinine were also highest in the urine of corresponding workers. A significant (P<0.01) correlation of r=0.86 Cr
and r=0.89 Ni was observed between airborne and urinary levels in all production workers. Approximately 26.6% of the
workers had respiratory diseases that were associated with wheezing, shortness of breath, sneezing attacks among
other related symptoms. Most of these workers were welders, tanners and, to lesser extent, paint manufacturers. The
breathing zone air of the afflicted workers had significantly (P<0.05) high mean levels of 6.4 ± 4.4 μg/m3 Ni and 9.6 ±
5.3 μg/m3 Cr than those who were not affected (3.9 ± 3.2 μg/m3 Ni and 4.4 ± 3.8 μg/m3 Cr). A high proportion of the
workers had reduced ventilatory function measurements. We recommend comprehensive assessment of Cr and Ni in
related industries with significant exposures. Designing and developing of training programs and educative manuals
on safety and health procedures, and regular medical surveillance is also recommended.

2012

FH, W, GN K, PM S, A WG, CM M.  2012.  Air and blood lead levels in lead acid battery recycling and manufacturing plants in Kenya. J. Occup Environ Hyg. 9(5):340-344. AbstractWebsite

The concentration of airborne and blood lead (Pb) was assessed in a Pb acid battery recycling plant and in a Pb acid battery manufacturing plant in Kenya. In the recycling plant, full-shift area samples taken across 5 days in several production sections showed a mean value ± standard deviation (SD) of 427 ± 124 μg/m(3), while area samples in the office area had a mean ± SD of 59.2 ± 22.7 μg/m(3). In the battery manufacturing plant, full-shift area samples taken across 5 days in several production areas showed a mean value ± SD of 349 ± 107 μg/m(3), while area samples in the office area had a mean ± SD of 55.2 ± 33.2 μg/m(3). All these mean values exceed the U.S. Occupational Safety and Health Administration's permissible exposure limit of 50 μg/m(3) as an 8-hr time-weighted average. In the battery recycling plant, production workers had a mean blood Pb level ± SD of 62.2 ± 12.7 μg/dL, and office workers had a mean blood Pb level ± SD of 43.4 ± 6.6 μg/dL. In the battery manufacturing plant, production workers had a mean blood Pb level ± SD of 59.5 ± 10.1 μg/dL, and office workers had a mean blood Pb level ± SD of 41.6 ± 7.4 μg/dL. All the measured blood Pb levels exceeded 30 μg/dL, which is the maximum blood Pb level recommended by the ACGIH(®). Observations made in these facilities revealed numerous sources of Pb exposure due to inadequacies in engineering controls, work practices, respirator use, and personal hygiene.

2011

Were, FH.  2011.  Use of human nails as a bio-indicator of heavy metals overload in children. (W. Njue, J. Murungi, R Wanjau, Eds.)., Nairobi: Kenyatta University Abstract

Metal pollution and its health effects present a challenge currently facing developing countries. Hair and nail were suggested as more attractive biomarkers among various biopsy materials (teeth, bone, urine, blood and other body fluids) in assessing human metal environmental exposure especially in developing countries because the analysis is economical and not susceptible to contaminations. Recent studies have indicated increasing levels of Pb and Cd in urban and agricultural areas. Studies have identified children as a special risk group as absorption and toxicity of toxic metals is inversely proportional to the age. Absorption of these metals in their gastrointestinal tract also depends on nutritional factors and interaction with other dietary components such as those of Zn, Fe and Ca. This study was therefore set to evaluate the concentration of Pb, Ca, Zn, Cd and Fe in the nails of children (n=200) under the age of six years as bioindicators of risk exposure. The concentrations of these metals were compared in toenails and fingernails samples of children (n=33). The sampling covered schools in both urban and rural settings. Factors that were suspected to influence the accumulation of Pb and Cd in children were obtained using a questionnaire. The atomic absorption spectrometry was used to determine the concentrations of the metals. The heavy metal levels in fingernails of children in urban areas were significantly higher than those of rural areas (P < 0.05; df = 168). The mean levels in urban areas were 27.5±1.8mg/g Pb and 0.73±0.08 mg/g Cd while those of rural areas were 19.7±0.9 mg/g Pb and 0.44±0.06 mg/g Cd. The correlation results indicated that high levels of Pb in the fingernail samples negatively correlated with Zn and Fe (R = -0.256 Zn; -0.188 Fe) but not Ca levels while high levels of Cd had a negative relationship with Fe (R = -0.241) only. Other factors that were found to have significant influence were socio-economic background, dietary habits and environmental risk exposure. The results also showed that the school location had more influence on the heavy metals level than the area of residence. The children in a school near the highway were found to have a mean of 34.4±3.5 NLm/g Pb as compared to those whose residence was near the highway (31.6±2.8 mg/g Pb), implying that the contaminants are from a common source. The study established that the mean metal levels were generally higher in the toenail than in fingernail samples. However, the difference was not significant (P > 0.05), therefore either the toenail or the fingernail could be used as bio-indicator. The association of toxic metals in the nails of children with environmental exposure and nutritional factors implies that policies and strategies to reduce the heavy metal levels should be implemented and reinforced to address the health issues affecting children in this country. This could be facilitated by improving the conditions of the schools and residential areas and sensitizing the general public on nutrition and effects of heavy metals.

2009

Faridah H Were, Njue WM, Murungi J, Wanjau R.  2009.  Comparison of Some Essential and Heavy Metals in the Toenails and Fingernails of School-Age Children in Kenya. Bull. Chem. Soc. Ethiop. 23(1):117-122. AbstractWebsite

This paper describes the determination of the levels of lead (Pb), cadmium (Cd), zinc (Zn),
calcium (Ca) and iron (Fe) in the toenails and fingernails of children under the age of six years in urban and rural
areas in Kenya by atomic absorption spectrophotometer. Lead levels in urban areas ranged from 8.0-49.0 μg/g in
fingernails and 7.0-62.0 μg/g in toenails as compared to those in rural areas (5.0-36.5 μg/g and 5.5-31.5 μg/g,
respectively). A similar trend was observed for Cd where significantly high levels were found in children in urban
areas than those in rural areas. The Fe and Zn levels were significantly higher in children in rural areas than those
in the urban areas. The levels of all the metals studied were higher in the toenails except for Fe and Ca where the
levels were higher in fingernails; however, the difference in the levels was not significant. These results indicate
that either the toenails or fingernails can be used as a reference for levels of metals environmental exposure.

2008

Were, FH, Njue W, Murungi J, Wanjau R.  2008.  Use of human nails as bio-indicators of heavy metals environmental exposure among school age children in Kenya.. Science of The Total Environment. 393(2-3):376-384. AbstractWebsite

Metal pollution and its health effects present a challenge currently facing the developing countries. Metal poisoning is usually difficult and expensive to assess or screen in these countries due to limited resources, which means that policies, guidelines, regulations and institutional managements are limited. Hair and nail as biopsy materials were suggested as more attractive biomarkers in assessing heavy metals environmental exposure. This paper deals with quantitative determination of lead (Pb), cadmium (Cd), calcium (Ca), zinc (Zn), and iron (Fe) in fingernails of children (n = 200) in urban and rural areas using atomic absorption spectrometry. Factors that were suspected to influence the accumulation of Pb and Cd in children were obtained through a questionnaire. The mean levels of heavy metals in children in urban areas were found to be higher (27.5 ± 1.8 μg/g Pb and 0.73 ± 0.08 μg/g Cd) than in rural areas (19.7 ± 0.9 μg/g Pb and 0.44 ± 0.06 μg/g Cd). The difference was significant (P < 0.05; DF = 168, t-test). Other factors that were found to have significant influence were socio-economic background, health conditions, dietary habits and environmental risk exposure. The results also showed that the school location has more influence on the heavy metals level than the area of residence. The children in a school near the highway were found to have a mean of 34.4 ± 3.5 μg/g Pb as compared to those who lived near the highway (31.6 ± 2.8 μg/g Pb), however the difference was not significant (P > 0.05), suggesting a common source of contaminants in the areas. The correlation results also indicated that a high level of Pb in the nail influenced negatively Zn and Fe but not Ca levels (R = − 0.256 Zn; − 0.188 Fe) while high levels of Cd had a negative relationship with Fe only (R = − 0.241). The association of toxic metals in the nails of children with environmental exposure, and nutritional status implies that policies and actions to reduce heavy metal levels must be implemented and reinforced to address the health issues affecting children and by extension the general public in this country.

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