OCCUPATIONAL EXPOSURE OF AUTOMOBILE MECHANICS TO PETROLEUM PRODUCTS

We carried out a  research  to investigate the potential risk of exposure to petroleum fumes among automobile mechanics in Lagos, Nigeria. Structured questionnaire was administered to elicit information on their exposure to petroleum products.  Automobile mechanics in their line of occupation are constantly exposed to petroleum products. These products contain toxic compounds such as Benzene, Toluene, Ethyl benzene and Xylene, (BTEX). Venous blood was taken from exposed subjects for Methaemoglobin (MetHb), Packed Cell Volume (PCV), haemoglobin and BTEX.

One of the effects of benzene in the body is the production of methaemoglobin (MetHb) which differs from haemoglobin. Haemoglobin accepts and transports oxygen only when the iron atom is in its ferrous form. When haemoglobin becomes oxidized, iron is converted to the ferric state (Fe3+) or MetHb. Methemoglobin cannot bind oxygen, MetHb lacks the electron that is needed to form a bond with oxygen and, thus, is incapable of oxygen transport.  

Our results reveal that the mean methaemoglobin value in the blood of the automobile mechanics (3.68%-7.33%) were significantly higher (p<0.05) than the control subjects (0.83%). MetHb level was directly proportional  to the duration of exposure with 0-5 years exposure having (0.4%) and 21-30 years of exposure having (13%).  We discovered that mechanics with many years of exposure has high MetHB in their blood. Since red blood cells are continuously exposed to various oxidant stresses, blood normally contains MetHb levels of between 1and 3% . Considering that MetHb has little affinity for oxygen, transport of the later to cells is hindered resulting in functional anaemia . As the level of MetHb increases, symptoms like shortness of breath, palpitation, anxiety and confusion occur . Humans are commonly exposed to benzene and other VOCs through the pulmonary and dermal pathways.

Methemoglobin saturation is expressed as the percentage of hemoglobin in the methemoglobin state; That is MetHb as a proportion of Hb.

·         1-2% Normal

·         Less than 10% metHb - No symptoms

·         10-20% metHb - Skin discoloration only (most notably on mucous membranes)

·         20-30% metHb - Anxiety, headache, dyspnea on exertion

·         30-50% metHb - Fatigue, confusion, dizziness, tachypnea, palpitations

·         50-70% metHb - Coma, seizures, arrhythmias, acidosis

·         Greater than 70% metHb - Death

Our study has established a strong evidence between increased exposure to petrol fumes among automobile mechanics and level of MetHb.   The awareness of effects of exposure to petroleum fumes and use of personal protective equipment by automobile mechanics to reduce exposure to petroleum products in their workshops is highly recommended.

Teaching Effectiveness: excerpt from Blendkit 2016 Online course

Teaching effectiveness describes instructors’ ability to affect student success. It is usually defined according to several factors, such as how well instructors organize courses, how well they know the course material, how clearly they communicate with students, how frequently they provide timely feedback, and other criteria. In the classroom, effectiveness sometimes depends on the instructor’s enthusiasm or disposition. During fully online and blended learning courses, students often need more structure and support to succeed because their course activities usually require them to take greater responsibility for their own learning success.

Therefore, many of the criteria take on even more importance when evaluating online teaching effectiveness. Online teaching is often held to higher standards than classroom teaching, and sometimes these standards have nothing to do with the teacher’s ability. For example, a technological breakdown can have a negative impact on students’ evaluation of an instructor’s work, though the instructor is rarely responsible for the technical failure.

Reference: Blendkit 2016 Readers digest

Understanding Blended Learning

What is Blended Learning?

Blended courses (also known as hybrid or mixed mode courses) are classes where a portion of the traditional face to face instruction is replaced by web based online learning. McGee and Reis (2012) point out that while there is not absolute agreement within higher education on the exact makeup of a blended course, institutions generally use “blended” (or related terms) to refer to some combination of on campus class meeting and online activities. Graham, Henrie, and Gibbons (2014) concur that “models adopting the [combining online and face to face instruction] definition are the most prominent in the research” (p. 21). Blended learning is a phenomenon subjected to much ongoing research. After reviewing over 200 masters’ theses and doctoral dissertations related to blended learning, Drysdale, Graham, Spring, and Halverson (2013) concluded that “more graduate research is being conducted on blended learning each year” (p. 98). Additionally, Picciano, Dziuban, and Graham (2014) have edited a collection of research on blended learning as a sequel to the landmark book published just seven years before (Picciano and Dziuban, 2007).

Benefits of Blended Learning

Blended course have proven to be among the most popular choices for students at institutions where they are offered (Olson, 2003 cited in Drysdale, Graham, Spring, and Halverson, 2013 and Kaleta, Garnham, and Aycock, 2005). At first glance, this popularity seems intuitive because blended courses allow students and faculty to take advantage of much of the flexibility and convenience of an online course while retaining the benefits of the face to face classroom experience. Although fully online learning has become well established in higher education, many institutions appear to be struggling with conceptualizing and implementing blended learning. Yet, where blended courses have succeeded, they have most often done so when strategically aligned with an institution’s mission and goals. The development and delivery of blended courses can be used to address a variety of institutional, faculty, and student needs. For universities, blended courses can be part of a strategy to compensate for limited classroom space, as well as a way to think differently about encouraging faculty collaboration. For faculty, blended courses can be a method to infuse new engagement opportunities into established courses or, for some, provide a transitional opportunity between fully face to face and fully online instruction.

For students, blended courses offer the conveniences of online learning combined with the social and instructional interactions that may not lend themselves to online delivery (e.g., lab sections or proctored assessments). If an institution’s blended learning strategy can be designed to address the needs and dynamics of all three constituencies (institution, faculty, and student) simultaneously, then blended learning can become a powerful force for institutional transformation.

Blendkit2016