There are now many alternatives to peat. Some of these, like garden compost and leaf mould, you can make yourself. Others, like mushroom compost, are widely available, often cost less than peat and are more valuable. The best way to control pests in the garden isn't by using pesticides, it's by encouraging their natural enemies. For example, birds, frogs and hedgehogs eat slugs and snails and ladybirds and hoverfly eat greenfly or their eggs.
Slug pellets kill more than just slugs.
They can kill hedgehogs, which eat the slugs and can even kill household pets. Consider planting a tree if you don't already have one. Trees filter air pollution, shelter birds and act as air conditioners, keeping areas shaded and cool. If there are a lot of trees near your garden then use the leaves in autumn to make your own leaf mould. Compost your garden and kitchen waste - and even your neighbours' garden waste if they don't want it.