Haematological profiles of Sudanese Traditional Bakery workers exposed to biomass burning hazards

Introduction:

Biomass burning has its origins since ancient times, in spite of the world has massive urbanization, a large section of resides in rural areas in developing countries remains using biomass burning in Traditional Cook Stoves (TCS). [1, 2] Most rural households approximately one-third of the world’s population in developing countries around three billion people were still depended on Solid Biomass Fuel (SBF) from materials including wood, sawdust, crop residue, dunk cake or coal for cooking, heating and other household activities energy needs.[3-6] Dependence on SBF (40%) leads to Indoor Air Pollution (IAP) which recognized as a major threat to human health. [2, 7] Short-term exposure to emissions from wood combustion known to be harmful to health from the combustion of fossil fuels which includes at least 28 pollutants in smoke from solid fuel use which have been shown to be toxic, including 14 carcinogenic compounds and 4 cancer-promoting agents. [5] Several health dangerous pollutants released by Burning of SBFs included Particulate Matters (PM), which declared carcinogenic by the International Agency for Research on Cancer, Carbon Monoxide (CO), Volatile Organic Compounds (VOCs) and, certain hydrocarbons includes Polycyclic Aromatic Hydrocarbons (PAHs) in the environment. [8-10] Numerous studies have mentioned that, (PM2.5) product of incomplete SBF combustion, is a component associated with climatic impacts and health effects. [3, 11] Concern the systemic effects of human health, air pollution, represent around 6% of the burden of disease, however, the World Health Organization (WHO) estimates that, more than 4.3 million deaths annually caused from smoke-induced diseases more than deaths caused by tuberculosis and malaria, which make it one of leading causes of deaths worldwide. According to the report by World Health Organization (WHO) in 2018, highest levels of exposure to PM2.5 may responsible in approx. 3.8 million premature deaths annually which includes respiratory and heart diseases. [12] In addition, CO is a colorless gas which have a serious effects, causing tissue hypoxia due to high binding capacity to hemoglobin and continuous exposure may result in neuropsychiatric impairment. [13-15] Workers in traditional bakeries, women, and children are the most vulnerable group who exposure to burning emissions in the kitchen area during cooking hours. [7, 8] Therefore, the impact of the concentration of pollutants from indoor biomass burning depends on many factors such as stove characteristics, kitchen characteristics, type and quantity of fuel, method of cooking, and ventilation influence the household indoor air quality (IAQ). [16, 17] Indoor air pollution from biomass combustion as exposure to wood smoke represent a major source of mortality and morbidity worldwide which has been associated with irritation of the mucous , physiological and neurological effects in human and may causes reduced lung function, increased risks of cardiovascular disease, stroke, lung cancer, pulmonary disease, chronic obstructive, acute lower respiratory infections, ischemic heart disease, low birth weight, preterm birth, stillbirth, stunting, cataracts, and all-cause mortality. [5, 18-22] Most of the Sudanese in rural areas are used biomass fuel mainly wood in their traditional bakeries. So, the current study aimed to determine the alterations and changes with regard to Haematological profiles to detect if there any significant difference between traditional bakeries who work more than three continuous years used wood and exposed to burning smoke and healthy individuals. It is important to note that this case has not been studied before.

Material and Methods:

Study Design and study Setting: A case-control study was done at White Nile State, Kosti, Kenana and Rabak towns, Sudan, from the period of June to November 2017 in order to study the effects of exposure to wood burning smoke on complete blood counts among Sudanese traditional bakeries workers exposed to burning smoke and working in traditional bakers more than three years contnsionally.

Participants and sample size: One-hundred traditional bakers were chosen to participate in this study as case group and another hundred healthy age and sex matching people were chosen as control group, from whom, 63% bakeries from Kosti, 21% from Rabak, and 16% from Kenana for both the cases and control.

Inclusion and Exclusion Criteria: All bakeries who work in Kosti, Rabak, and Kenana and exposure to wood burning smoke more than three continuous years working were included in this study. Participants who had cardiovascular disease, presence with Blood diseases, current drugs effect on Complete blood counts (CBC), Smokers, alcoholism, children and worker period less than three continuous and those who refused to participate were excluded.

Data Collection: Structural interviewing questionnaire was used to collect data. It included personal and clinical information and laboratory investigations.

Laboratory Analysis: 2.5ml venous blood samples were collected from each participant into (EDTA) Ethylene Diamine Tetra Acetic Acid containers, labelled, mixed, and checked for absence of clots, and examined immediately for full blood counts (FBC) using automated haematology analyser (KX-21 Sysmex®, Tokyo, Japan). Peripheral blood films for morphology was done using Giemsa stain and differential counts was done microscopically.

Statistical analysis: Laboratory and demographic data were analysed by Statistical Package for the Social Sciences, IBM SPSSversion-25. Mean, standard deviation and Frequency distribution were performed. Comparison was done by applying two-tailed Student's t-test to know the difference between traditional bakeries workers haematological values and the healthy control group laboratory results. Alpha error of 0.05 and P value ≤0.05 were considered as level of significance.

Ethical considerations: Each participant completed the informed consent form before collecting the specimens. Ethical approval was obtained from the research and ethics committee at University of El Imam El Mahdi, Faculty of Medical laboratory Sciences.

Results: The findings of the current study showed that, 100% of the study participants were male because female normally in Sudan didn’t work in bakers. 50%of the study group and controls between 30-39 years old, 32% between 20-39 years old, and the remaining 18% between 40-49 years old. The results of haematological parameters indicated that, the mean of Hb, HCT, MCH, MCHC, MCV, platelet counts, and Neutrophil counts values among bakeries group were statistically significantly decreased comparing with the control group, the mean of the Haemoglobin (12.58±2.15 g/dl vs. 15.15±0.95 g/dl ;P=0.000), HCT (42.71±6.14 l/l vs. 44.72±4.15 l/l ;P=0.000), HCH (27.72±2.83 pg vs. 29.41±1.88pg; P=0.000), HCHC (30.75±2.64%vs. 32.33±2.26%; P=0.000), MCV (83.49±6.43fl vs. 89.18±7.15 fl; P=0.000), platelet counts (205.29±51.49×103/l vs. 238.11±59.56×103/l; P=0.000), Neutrophil counts (49.59±16.43% vs. 57.36±13.93% ;P=0.000). (See Table 1, 2, 3). However, the mean of TWBCs counts (6.77±1.71×103/l vs. 6.17±1.50×103/l; P=0.007), and the mean of lymphocyte counts (36.21±13.52% vs. 29.98±5.70%; P=0.000), were statistically significantly increased in bakeries (SeeTable3). The mean of RBCs counts (4.89±0.6×1012vs. 4.90±0.42×1012; P=0.000), had no statistically significant difference between bakeries and apparent healthy control group (See Table 2). The microscopically blood morphology of the traditional bakeries workers, showed that, 37% of the participants RBCs normocytic normochromic picture, 34% normal with stomatocyte cells, 17% dimorphic picture, 6% normal with target cells, and 4% normal with spherocyte, and 2% showed microcytic hypochromic picture. (See Table4)

Table 1: Haemoglobin concentration (Hb) and haematocrit blood test (HCT) values among Traditional bakeries exposed to Wood burning and controls.
Parameter	Study group traditional bakeries n=100	Control group apparent healthy individuals n=100	t- value	P-value*
Category	Frequency	percent	Mean ±SD	Category	Frequency	percent	Mean ±SD
Hb concentration	12-17 g/dl	52	52%	12.58±2.15 g/dl	12-17 g/dl	87	87%	15.15±0.95 g/dl	10.924	<0.001
<12 g/dl	48	48%	<12 g/dl	9	9%
>17 g/dl	0%	0%	>17 g/dl	4	4%
Total	100	100%	Total	100	100%
HCT	45.5 l/l-41.5 l/l	59	59%	42.71±3.44 l/l	45.5 l/l-41.5 l/l	93	93%	44.72±1.05 l/l	5.605	<0.001
<41.±.5 l/l	37	37%	<41.±.5 l/l	5	5%
>45±.5 l/l	4	4%	>45±.5 l/l	2	2%
Total	100	100%	Total	100	100%

Table 2: RBCs counts and red cell indices (MCV, MCH, and MCHC) values among Traditional bakeries exposed to Wood burning and controls.
Parameter	Study group traditional bakeries n=100	Control group apparent healthy individuals n=100	t- value	P-value*
Category	Frequency	percent	Mean ±SD	Category	Frequency	percent	Mean ±SD
RBCs counts	3.8-5.5 × 1012	52	52%	4.89±0.61 ×1012	3.8-5.5 × 1012	85	85%	4.90±0.42 × 1012	0.068	0.946
<3.8× 1012	31	31%	<3.8× 1012	12	12%
>5.5 × 1012	17	17%	>5.5 × 1012	3	3%
Total	100	100%	Total	100	100%
MCV	92.0±9 fl	48	48%	83.49±6.43 fl	92.0±9 fl	87	87%	89.18±7.15 fl	5.919	<0.001
<83fl	52	52%	<83fl	11	11%
>101fl	0	0%	>101fl	2	2%
Total	100	100%	Total	100	100%
MCH	29.5±2.5pg	53	53%	27.72±2.83 pg	29.5±2.5pg	91	91%	29.41±1.88pg	4.974	<0.001
<27 pg	42	42%	<27 pg	6	6%
>32 pg	5	5%	>32 pg	3	3%
Total	100	100%	Total	100	100%
MCHC	33±2.5 %	49	49%	30.75±2.64%	33±2.5 %	83	83%	32.33±2.26%	4.564	<0.001
<30.5 %	43	43%	<30.5 %	5	5%
>35.5 %	8	8%	>35.5 %	12	12%
Total	100	100%	Total	100	100%

Table 4: Microscopically Morphology among traditional bakeries.
Percent	Frequency	Microscopically Morphology
37.0	37	Normocytic normochromic
17.0	17	Dimorphic
2.0	2	Microcytic hypochromic
34.0	34	Normal with stomatocyte
6.0	6	Normal with target
4.0	4	Normal with spherocyte
100	100	Total

*Significance at the level ≤0.05

*Significance at the level ≤0.05

Table 3: TWBCs counts, PLTs counts, Neutrophil counts, and Lymphocytes counts values among Traditional bakeries exposed to Wood burning and controls.
Parameter	Study group traditional bakeries n=100	Control group apparent healthy individuals n=100	t- value	P-value*
Category	Frequency	percent	Mean ±SD	Category	Frequency	percent	Mean ±SD
TWBCs counts	4-10 ×103 /l	95	95%	6.77±1.71×103/l	4-10 ×103 /l	97	97%	6.17±1.50×103/l	2.740	<0.007
<4×103 /l	4	4%	<4×103 /l	2	2%
>10 ×103 /l	1	1%	>10 ×103 /l	1	1%
Total	100	100%	Total	100	100%
PLTs counts	170-450×103/l	88	88%	205.29±51.49×103/l	170-450×103/l	93	93%	238.11±59.56×103/l	4.168	<0.001
<170×103 /l	12	12%	<170×103 /l	5	5%
>450 ×103 /l	0	0%	>450 ×103 /l	2	2%
Total	100	100%	Total	100	100%
Neutrophil counts	40-80%	64	64%	49.59±16.43%	40-80%	89	89%	57.36±13.93%	3.607	<0.001
<40%	36	36%	<40%	9	9%
>80%	0	0%	>80%	2	2%
Total	100	100%	Total	100	100%
Lymphocytes counts	20-40%	50	50%	36.21±13.52%	20-40%	83	83%	29.98±5.70%	4.246	<0.001
<20%	9	9%	<20%	6	6%
>40%	41	41%	>40%	11	11%
Total	100	100%	Total	100	100%

*Significance at the level ≤0.05

Discussion: The exposure to biomass smoke and PAHs induces oxidative stress, represents an imbalance between pro-oxidants and antioxidants system causing haemolysis which leads to the free heme acts as proxidants and contributes to inflammatory events by increasing the expression of vascular adhesion molecules during haemolysis, however, recent studies has provided evidence of association between wood smoke emissions mainly PAH exposure and probable impairments on blood parameters in human. [23-26] The traditional bakeries workers used wood as a fuel and exposure to both air pollutants and high temperature. The results of the current study showed that, 100% of the study participants were male because the Sudanese female didn’t normally work in bakers and fuel stations. [27] Approximately half of our study group and controls between their 30-39 years old, 32% between 20 - 29 years old, and the remaining 18% between their 40-49 years old, so, the majority of workers 82% are youth before their forties years old. Haematological parameters results indicated that the Hb, HCT, MCH, MCHC, MCV, platelet counts, and Neutrophil counts values were statistically significantly decreased among bakeries group comparing with the control group, the mean of the Haemoglobin (12.58±2.15 g/dl vs. 15.15±0.95 g/dl ;P=0.000), HCT (42.71±6.14 l/l vs. 44.72±4.15 l/l ;P=0.000), HCH (27.72±2.83 pg vs. 29.41±1.88pg; P=0.000), HCHC (30.75±2.64%vs. 32.33±2.26%; P=0.000), MCV (83.49±6.43fl vs. 89.18±7.15 fl; P=0.000), platelet counts (205.29±51.49×103/l vs. 238.11±59.56×103/l; P=0.000), Neutrophil counts (49.59±16.43% vs. 57.36±13.93% ;P=0.000). (SeeTable1, 2, 3). The findings of this study go in line with previous studies done in Ghana in 2019 by Dadzie EK. and his colleagues [28] who indicted, low hemoglobin, low MCV, low MCH, low MCHC, and low GRAN which significantly associated with exposure to wood smoke, and study done in Pakistan in 2016 by Kamal A, and his colleagues [29] who found low hemoglobin level (Hb) in subjects who prolonged exposure to combustion of large amounts of fuel wood and coal smoke, also it is in agreement with the another study done in India by Padhy PK. and his colleagues in 2009 [30] reported that, the children who live in households cooking using traditional biomass fuels had low Hb levels, but not in agreement regarding neutrophil counts which found increased in the traditional biomass fuels exposed. In contrast the study done in Tandoor in 2014 by Nabi G, et al. [31] stated, high Hb, high HCT, high MCV, High MCHC, High RBCs counts, high lymphocyte counts, and high Platelet counts among Tandoor Occupants who exposed to Wood Smoke when comparing to healthy control persons, however the same study in agreement with the current study results regarding decreased neutrophil counts, increased lymphocyte counts and increased TWBCs counts. On the other hand, the results concluded by Rabha R. and his colleagues in India during 2018, [32] revealed that, platelet counts had a significant positive association results from emissions released during cooking with fuel wood while haemoglobin had a negative association. The mean of TWBCs counts (6.77±1.71×103/l vs. 6.17±1.50×103/l; P=0.007), and the mean of lymphocyte counts (36.21±13.52% vs. 29.98±5.70%; P=0.000), were statistically significantly increased in bakeries (SeeTable3). Similar results stated in the previous studies [30, 31, 32] and high white blood cell count also concluded by previous study done in Pakistan in 2016 by Kamal A, and his colleagues [29]. Regarding high lymphocyte counts the current study findings agreement with the previous study done in Ghana in 2019 by Dadzie EK and his colleagues [28]. The mean of RBCs counts (4.89±0.6×1012vs. 4.90±0.42×1012 ;P=0.000), had no statistically significant difference between bakeries and apparent healthy control group (See Table 2), these results in contrast with the study done in India by Padhy PK and his colleagues in 2009[30] who reported low red blood cell (RBC) among wood smoke exposure and study done in Tandoor in 2014 by Nabi G, et al. [31] who stated high RBCs count. The microscopically blood morphology of the traditional bakeries workers, showed that, 37% of the participants RBCs showed normocytic normochromic picture, 34% showed normal with stomatocyte cells, 17% showed dimorphic picture, 6%showed normal with target cells, 4% showed Normal with spherocyte, and 2% showed microcytic hypochromic picture (SeeTable4). Changes in hematologic parameters in this study were similar to those findings, in a study conducted by Lal et al. in 2011[33] who measured haematological parameters in rodents, exposed to cow dung smoke for around 12 months.

Conclusion:

The present study results showed apparent significant effects approximately in the all haematological parameters values among traditional bakeries who exposed to wood burning smoke.

Funding: Personal

Conflict of Interest: The author declared no conflict of interests.

Acknowledgment: The author would like to thank participants and his collagenous

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