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chem1b Transcribed by TurboScribe.ai. Go Unlimited to remove this message. of hazardous waste and prevent illegal trafficking chemicals. Key provisions in this convention is the requirement of informed consent before exporting hazardous waste, ensuring environmentally sound waste management process...

chem1b Transcribed by TurboScribe.ai. Go Unlimited to remove this message. of hazardous waste and prevent illegal trafficking chemicals. Key provisions in this convention is the requirement of informed consent before exporting hazardous waste, ensuring environmentally sound waste management processes and reducing hazardous waste generation. This is quite a significant convention because it's the first global agreement on hazardous waste management and it marks a big step and an important step in international environmental law. I think it's very relevant, for example, for resource-scarce countries and it provides a level of protection against perhaps wealthier countries exporting their waste perhaps to a country that might be vulnerable to this process if they don't have the requirements set out in the convention set in place. So the next convention is the Rotterdam Convention. It was adopted in 1998 and entered into force in 2004 and the objective of the convention is to motiate responsibilities in the import and export of hazardous chemicals through what's called a prior informed consent procedure. So what this procedure means is that exporting countries must notify and obtain consent from importing countries before proceeding. So this allows for improved communication. It also allows for informed decision-making of both the exporting and importing countries and it ensures that both countries are aware of and agree to the process of the importation of hazardous chemicals. Then we have the Stockholm Convention which was adopted in 2001 and entered into force in 2004 and this convention focusses specifically on persistent organic pollutants or POPs and POPs are chemicals that persist in the environment that can bioaccumulate through the food chain and they pose a risk of causing adverse effects to human health and also to the environment. The aim of the Stockholm Convention is to eliminate or restrict the production and use of POPs and it started with an initial list of 12 POPs known as the dirty dozen. So the convention includes measures to reduce or eliminate release of unintentional POP production and also provides for the safe disposal of POP stockpiles. And then lastly we have the Malamarta Convention. So these are conventions I'm highlighting and of course there are other conventions that would also be relevant. We'll just touch on these four today. So the Malamarta Convention on mercury adopted in 2013 and entered into force in 2017 is a global treaty to protect human health and also the environment from the adverse effects of mercury. So if you have time you could google mercury and Malamarta on YouTube and it's a very interesting story related to Malamarta Bay in Japan. There was industrial mercury pollution into the bay and the fish became toxic. The residents ate the fish and it impacted the whole food chain. It's a very interesting case study and it's worth looking up. So mercury is a potent neurotoxin and it can have very severe health effects. The Malamarta Convention includes measures such as banning new mercury mines, phasing out existing ones, controlling air emissions and regulating mercury added products and processes. So it's quite an important convention to be aware of. These conventions have very different focusses. However they share common goals. They all look at protecting human health and the environment from the adverse effects of hazardous chemicals and waste. They promote safe handling and use of chemicals throughout the chemical life cycle. They enhance international cooperation and information exchange between countries to address chemical risks. They support developing countries to build capacity and provide for sound chemical management. And they provide for the reduction and elimination and also prevent the release of hazardous chemicals and waste into the environment. It's quite abstract. So trying to bring it back to occupational medicine. So as professionals in occupational medicine, through being aware of the conventions, you can play a very important role in supporting the objectives of the different international conventions and in our respective environments. This could be through worker protection. So as occupational medicine doctors we have responsibility for identifying and managing chemical exposures in the workplace and helping ensure that workers are protected from hazardous substances. Depending on our MCA in the organisation, we may be involved in policy development so we can advise on regulations and also compliance with international conventions and help shape policies within respective organisations that promote chemical safety. We can advocate for education and training. We may be involved in education and training and this raises awareness among both workers and employers about chemical risks and safe practises and overall this contributes to building a culture of safety. And then we have a very important role to play in research and monitoring. So our work as occupational medicine doctors can add to the body of data on chemical hazards and this is really important in a data-scarce environment which somewhat exists in lower middle-income countries and this can inform future policy and practise. Okay so I'll take two minutes. Are there any questions at this stage? There's a question from Dr Modley who's asking what is silica? I suppose I think in like what form. Yeah that's the question. Okay well that's a good question. So silica is a mineral that can find both a mining environment but also you get non-mining silica exposure and we'll have a whole lecture on silica because it's very important occupational exposure but silica exposure usually occurs through dust and so silica does and that can have various respiratory health epics and non-respiratory epics. I'm not sure if you'd like more detail. We are going to cover silica later in the course. It's very important. So when it comes to dust, silica, asbestos, coal are the sort of the three big ticket items which we are going to cover. She says that's fine thanks. Okay anything else? Guys you're all welcome to unmute and I'm also asking if you don't put it in the chat. Okay so I'll carry on. Okay so the globally harmonised system of classification and labelling of chemicals. The GHS is something also that one must be aware of when working with chemicals and the GHS essentially is a framework or guidance for classifying and labelling hazardous chemicals. The GHS is also known as the purple book and if you if we're in the lecture and you google GHS purple book you'll come across the full document. It's about 400 pages but this system was developed by the United Nations to allow for international standardisation and classification and also labelling of chemicals. So the objective of the GHS is to ensure that information about chemical hazards is available globally. It's understandable regardless of where chemicals are produced or where the chemical is used. Once again this is an introduction to the system but we'll have a whole lecture on the GHS. The GHS has a number of key components and these include consistent hazard classification criteria. It includes standardised label elements and pictograms and signal words. One is familiar with the GHS system. If one sees a specific pictogram or signal word on any chemical document you immediately know what that stands for. The GHS also involves a standardised format for chemical information known as safety data sheets. So South Africa has actually promulgated the GHS into legislation and it may be worthwhile maybe for those of you from Namibia, from Botswana, from Tanzania, go back and see whether it's been integrated into legislation in your countries. The GHS is a very important system because it facilitates international trade. It enhances protection of human health and sits a specific benchmark and it also enhances protection of the environment through promoting common understanding of chemical hazards. We'll come back to this when we get into more detail. I'll briefly look now at South African legislation. Very, very brief overview. Once again there's a lot more to discuss and we'll have a detailed lecture which I think Dr. Mankiewicz will present. Okay, so the most important piece of legislation related to workplace chemical hazards in South Africa is the regulations for hazardous chemical agents. I think the most recent version was promulgated in 2022. The regulations outline a number of different duties and responsibilities. I'm going to go through this slide in detail. Firstly the regulations outline the duties of persons who may be exposed to hazardous chemical agents. So anyone who may be exposed, an employer may be exposed, must obey the instructions given or provided by the employer regarding various aspects related to prevention, housekeeping and training. The regulations provide clear guidance on the assessment of exposure and that's outlined in detail and it provides guidance on air monitoring so with an inhalational risk. At present the employer must ensure a measurement programme of the airborne concentration of the hazardous chemical agents at least every 24 months or two years. The regulations outline the requirements for medical surveillance. The certain conditions are present as outlined in the regulations. If the employee might be exposed to an HCA this is entailed before the regulations. If the exposure to the chemical agent might lead to identifiable disease and there's a reasonable likelihood that this disease may occur under the conditions of their work. There are techniques to diagnose the disease. Also a programme of medical surveillance is required and lastly if the occupational health practitioner recommends that the employee should be under medical surveillance then this programme should be set in place. The regulations outline the structure of the medical surveillance programme, the initial health assessment immediately before the 14 days of when an employee commences employment and what this evaluation should consist of so the medical and occupational history should include a physical examination and any other examination which in the opinion of the occupational health practitioner is required in order for the occupational practitioner to complete the assessment. And then the requirements for regular healthy evaluation that intervals not exceeding two years or as specified by the occupational medicine practitioner. The regulations outline the requirements for respirator zones and it should be clearly demarcated and the requirement that anyone entering or remaining in a permanent respirator zone should be wearing the required personal protective equipment. And I think importantly the regulations outline very specific control measures so they provide very clear guidance on control measures according to the hierarchy of controls. So the next few slides are taken from the regulations and we will come back to this and it's just an overview. The regulations start out in the note that the HCA should be eliminated and completely removed or a substitute should be used. If this is not possible the regulations outline the following measures. It outlines engineering controls noting process separation, automation or enclosure. The regulations outline the installation of local extraction ventilation systems for the control of emission of an airborne HCA. It also mentions the use of wet knickers. So wet knickers are mainly applicable in dust environments and they refer to spraying water in the production process to reduce dust and other airborne particulate matter. So it's the goal of preventing employees inhaling polluted air. And then lastly the regulations mention the separation of workplaces for different processes. Under administrative measures the regulations refer to appropriate work procedures on safe hazardous chemical agent handling. It refers to appropriate work procedures on the safe use and maintenance of machinery installations equipment tools and local extraction and general ventilation system. It should be appropriate procedures on keeping machinery and work areas clean. Lastly there should be procedures on early identification and corrective action. The regulations also outline administrative controls related to limiting the amount of the HCA used and limiting the number of employees who will be exposed or might be exposed and limiting the period during which an employee will be exposed or might be exposed. Lastly the regulations refer to personal protective equipment and it specifically mentions suitable respiratory protective equipment and also it refers to protective clothing and the skin absorption of certain hazardous chemical agents. Where the HCA can be absorbed to the skin the regulations stipulate that suitable impermeable protective equipment should be provided. But as I said it's an overview and the conventions the GH system and the legislation will be covered in more detail in the incoming lectures. Okay so briefly look at the chemical hazard identification and risk assessment process and a few nuances related to the chemical risk assessment. So at this stage we're all familiar with the highway process and so the chemical hires usually provides a systematic approach to recognising all chemicals present in the workplace that can potentially cause harm. The goal of the chemical hire is to identify hazardous chemicals and so those that might be produced in the workplace as it might be used in the work environment or chemical hazards that might be generated as byproducts of production or processes. Secondly the hire needs to and through completing the hire we need to understand the nature of the hazards associated with each chemical so the potential for an adverse health effect and really pull back on the properties such as toxicity, flammability, the reactivity for example and the various other characteristics I mentioned earlier in the lecture. And then last we need to understand who may be exposed to the hazards in the work environment and the pathways through which exposure occurs. So chemical hiring or the hazard identification process involves several important steps. There needs to be a step involving gathering information so even before we set foot into the workplace there needs to be an inventory created of all chemicals that are present in the work environment. This has to include chemicals in production, so raw materials, intermediate materials, the finished product and then also importantly waste materials and to review all processes and all tasks to understand when and how chemicals might be used or produced or occur as a result of byproducts in the work environment. When we refer to safety data sheets the next step is to review the safety data sheets. So I mentioned the safety data sheets and these are important because a well-structured safety data sheet provides detailed information on the properties of the chemical including the hazards associated with the chemical and other information such as handling precautions and emergency measures. And once we've gathered our information and we've done our research we then can go into the workplace and observe. There we do our workplace inspection and we look at any orders that might have been performed and we observe how chemicals are stored, how the chemicals are handled, how the chemicals are disposed, how the workers interact with the chemicals and are they entering the food area and eating lunch without washing their hands for example. So you can look for any potential issues related to labour, storage, use and interaction of chemicals. And then lastly we consider interviewing the employees, speaking to workers, gaining insight into what's happening on the ground. Have there been any near misses or any specific concerns related to the chemical use. So just a note on the chemical inventory. So the chemical inventory is the foundation of the chemical hazard identification process. It's very important to list all chemicals present at the beginning including those in storage and also those in use along with the quantities. And you might want to sum out as the process as you go along in the process. But through this process you understand how chemicals are used, whether they change form during use or byproducts and always might be a result of the workplace processes. So this can be quite a bit of information. Sometimes it's useful to use software tools or databases and even an Excel spreadsheet could be a very basic useful tool to use to manage the information efficiently and ensure that you can retrieve the information in an efficient manner and update your chemical inventory as you complete your risk assessment and as information might develop or change. So I've mentioned safety data sheets. So I don't think I need to go through the whole slide, but just to note that the SDS is essential, an essential part of the chemical hierarchy. So they offer information on the actual hazard itself. And then there might be other useful pieces of information related to first aid measures, handling of storage of the chemical, and exposure controls and PPE requirements. And then SDS is a regulatory requirement. So employers should have SDSs available for review, at least in South Africa. So once we've completed the hazard identification aspect of the hierarchy, we can move to the risk assessment aspect. And our chemical hazard identification feeds into our risk assessment. The components of the risk assessment include the exposure assessment, our dose response assessment, and the risk characterisation. So exposure assessment would be finding out who is exposed, to what extent or degree they are exposed, and the frequency of exposure, how often exposure occurs. Dose response assessment is a very important part of the chemical risk assessment and involves understanding the relationship between the dose and the occurrence of effects. And then risk characterisation involves integrating all of the information gained into a value to quantify the risk, or to describe the nature and magnitude of the risk, and allow us to rank risk and prioritise the risk. And then finally this will feed into our recommended chemical measures. In terms of the risk assessment process, it's very important to understand certain toxicological principles. And we'll be having a separate lecture on a few of these principles. I'm just touching on them today. So toxicology is the study of chemicals' adverse effects on living organisms, and it helps us understand how chemicals can cause harm. And this is essential for our performing an effective risk assessment. So by applying principles of toxicology in the risk assessment process, we can gain data on the inherent hazards of the chemicals, and it informs our assessment of the dose-response relationships, which allows us to quantify the risk. It allows us to identify the mechanisms of toxicity, so understanding how chemicals interact with the human body. And then also this then helps us to understand the potential health effects associated with chemical exposure, and it guides us in exposure limits and safety standards to protect workers. So key toxicological concepts we'll come across in the next few weeks. And it is, so first the absorption, distribution, metabolism, and excretion of toxic aerodynamics and toxic kinetics. So we'll have to understand principles related to how the chemical enters the body, how it's distributed to different tissues, the metabolism or transformation, and how chemicals are eliminated. And this ultimately influences the internal dose and the potential toxicity. And we'll look at principles related to acute toxicity. So acute effects after a single exposure or multiple exposures in a very short period of time, such as burns or poisoning, chronic toxicity, which is effects resulting from long-term exposure, often at low levels, and usually this relates to health effects such as cancer or worker damage, such as perhaps chronic renal disease. And then we have to understand the mechanisms of action, so how chemicals can cause harm at the molecular or cellular level. This might be more relevant to the registrars, so we might not go into that much detail in the course, and then also understand target for those systems. Okay, so a few concepts which I've already mentioned is the dose-response relationship, and that's really the cornerstone of our assessment. And then we also assess the threshold effects, and that would relate to what is COVID-ready. So the principles relate to stochastic and deterministic effects. We also apply when completing the chemical risk assessment. Okay, so we'll have a longer lecture on toxicology. And then lastly, the health and environment and mental effects. So chemical hazards, there's a lot of overlap between occupational health and environmental health when we consider chemical hazards. For the most part, we'll be looking at the health effects, and we'll cover this when we cover the GHX. The GHX categorises the different health effects in quite a structured manner. So we'll cover a broad approach, which is outlined on the slide. And then as we work through the different chemicals, we'll learn about the different health effects specific to the different chemical exposures, so for silica, nitrosilicosis, and asbestos, and asbestosis, mesothelioma, cold, cold winters, pneumoconias. So we'll systematically work through the different health effects as we cover the different chemicals. Okay, so that's all I said about the health effects for now. And then there's a short video, which sort of summarises everything I've just said. I can play the video, or you can watch it when you review the slides. You can maybe have a vote. So, Casper, could you see, if anyone would like to see the video, can they give a thumbs up? Casper and Charlie, can you count the votes? We have got a majority thumbs up. I agree. Okay, so we'll play the video. This file is longer than 30 minutes. Go Unlimited at TurboScribe.ai to transcribe files up to 10 hours long.