Yeah it's a really tough problem with no clear answers.
Microplastics and other pollutants with potential long-acting health impacts are very hard to predict far in advance. Strong evidence for or against any adverse health effects would take considerable effort to gather while in the mean time they offers such clear advantages and solve so many problems. Plastics have massively reduced costs in almost every industry and have become almost irreplaceable in some applications such as medical equipment (think packaging for syringes, surgical tools, or anything that requires contamination control).
With lead there were viable cost-effective alternatives, it wasn't in nearly every product we consume, and we already had pretty clear evidence that its highly toxic so the only evidence needed was to show that the low levels being used in gasoline, while not acutely toxic, could be harmful given enough exposure to it over time.
I doubt anyone working on plastics early on anticipated microplastics would end up in nearly all of our food, living spaces, and even build up in our bodies. By the time there would be any alarm bells sounding, it would've been too late, the sheer number and ways it solves problems makes it far too difficult to retreat from when, due to the nature of how its potential effects could arise, wouldn't give any strong evidence that its harmful.
Outside of plastics many air pollutants are similar in that manner. The processes that release them are so convenient and solve so many problems, while any health effects would be long-term and extremely difficult to gather strong evidence for.
Microplastics and other pollutants with potential long-acting health impacts are very hard to predict far in advance. Strong evidence for or against any adverse health effects would take considerable effort to gather while in the mean time they offers such clear advantages and solve so many problems. Plastics have massively reduced costs in almost every industry and have become almost irreplaceable in some applications such as medical equipment (think packaging for syringes, surgical tools, or anything that requires contamination control).
With lead there were viable cost-effective alternatives, it wasn't in nearly every product we consume, and we already had pretty clear evidence that its highly toxic so the only evidence needed was to show that the low levels being used in gasoline, while not acutely toxic, could be harmful given enough exposure to it over time.
I doubt anyone working on plastics early on anticipated microplastics would end up in nearly all of our food, living spaces, and even build up in our bodies. By the time there would be any alarm bells sounding, it would've been too late, the sheer number and ways it solves problems makes it far too difficult to retreat from when, due to the nature of how its potential effects could arise, wouldn't give any strong evidence that its harmful.
Outside of plastics many air pollutants are similar in that manner. The processes that release them are so convenient and solve so many problems, while any health effects would be long-term and extremely difficult to gather strong evidence for.