The quality of the image can be improved, and the font can be bigger.
I would also invite the author to complicate the visualization of temporality —how to complicate the linear representation of time?
Reading the caption, I was reminded of a book I recently read, "In the Wake: On Blackness and Being" by Christina Sharpe. I would recommend revising it to think further and perhaps conceptualize the visual practice of annotation and redaction. I am particularly thinking of chapter 4, section Black Annotation and Black Redaction.
In that sense, I would recommend using the caption to think/reflect on the visual intervention itself, not only to address what it reveals about the temporality of toxics but also about visualization as an ethnographic practice.
This visualization creates a temporary toxicity inventory in Pasadena, California. Based on a series of documents, the author illustrates how the discursive practices that make toxicity or the slogan invisible in the distant past can be visually intervened. This intervention illuminates what was erased or circumscribed to the past, transforming it into a colorful visual representation of the (lineal) temporalities of toxicity.